What makes a spellcasting component worth x gp?

Question

Let's just pick on identify as a concrete example, but this applies to any spell with a material component with a cost. So identify requires a pearl worth 100gp. What makes a pearl worth 100gp?

Is it the price paid to acquire it, or the price it would go for if sold? If the former, if my PC was ripped off and got a cheap pearl (that most people would only sell for, say, 20gp) but paid 100gp for it, would that work under the reasoning that the only way to value something is on how much someone is willing to pay for it?

Alternately, what if a PC made an awesome Charisma roll and convinced a merchant to sell what would have normally been a 100gp pearl for 80gp? Does it still count as a 100gp pearl for spell purposes or does the spell somehow recognize that its caster only paid 80gp for the pearl and refuse to work?

What if they got an actual 100gp pearl, but then dropped it and it got chipped slightly, no doubt reducing its price to potential buyers but is still a whole and mostly undamaged pearl for the purposes of spellcasting, would it still count as a pearl worth 100gp to cast identify with?

I suppose I'm just trying to understand the relationship between the arbitrary object needed for certain spells and their price requirement. What exactly makes any gem, or any object at all, worth a certain amount for the purposes of satisfying the material component requirements? How would the spell "know" how much it costs? In other words, is the value of a component with respect to spellcasting innate to the object itself or does it track the market? If it tracks the market, does it only "care" about how much was paid for itself or does it also track local and/or regional markets? For example, if a PC purchases an 100gp pearl and then travels to a land where pearls are plentiful and such pearls can be had for only 70gp, can the PC still use the pearl or does it become a 70gp pearl?

The reason I ask is because I'm wondering if there's any way to make an object worthless in terms of commerce (so that no-one would want to buy, say, this specific pearl) but at the same time have it still be valid for identify. This is so that an item, once acquired, isn't something that can just be flogged, but something that only has the singular use of being for that exact spell.

Answer 1

No, buying a cheap pearl for 100 gp doesn't work

The rules say "worth at least 100 gp", not "bought for at least 100 gp". If you buy a cheap pearl from another character for 100 gp, it doesn't become 100 gp worth. And vice versa, if you steal a 100-gp pearl for free, it is still 100 gp worth. This is true for any items, not only for material spell components. The item's cost is determined by a few factors, including the item's quality. So, the item's cost is a (very) rough equivalent of the item's quality. So, why the PH specifies the cost, instead of describing the quality?

Specifying a cost is much easier than describing a quality

Aside from the seller's insights, nothing specific makes an item worth X gp.

"Worth at least X gp" is a short, convenient indication of the item's quality. 5e PH does not describe any specific criteria of "worthing X gp" (hence, being suited for the spell) - it only says the item's guiding price, one number instead of a bunch of words. It's the DM who should decide and say "unfortunately, this pearl is too cheap and small to be used for this spell".

Let's elaborate the pearl example. Instead of "worth at least 100 gp" the PH might describe its minimum weight, radius, material, shape, surface quality, etc. PH had to describe such criteria for every single material component in this way, which contradicts the 5e paradigm. Instead, the PH just says "worth at least 100 gp" - so both DM and players get an idea, what kind of pearl it should be.

Your DM might go the easy way

It really depends on the playstyle, but a DM might decide that market conditions is not a thing in their world. Instead, he/she might take all the prices from the PH and use them as absolute prices, instead of guiding ones. Using static prices model solves many buying/selling questions, but in the end leads to hilarious absurdities as a downside, which might not be welcomed by players.

Answer 2

Value is absolute

The rules of D&D seem to assume that value is absolute, not relative. That is to say, things have the value that they have (especially precious items like gems and jewels, artwork, precious metals, etc.) and that's unrelated to how much you might be able to actually buy and sell them for in your present circumstances. A 100gp pearl is a 100gp pearl - whether you found it in an oyster yourself, got given it as a gift, bought it for 50gp in a display of stunning haggling or got ripped off and thought you were getting something worth 200gp.

I would judge that it remains a 100gp pearl even if you go to the Elemental Plane of Pearls and come back with a bag of holding filled to the brim with incredibly valuable pearls and start giving them out on the streets like candy - which, in any sensible economy, would quite rapidly devalue pearls (not that D&D has rules for that kind of thing, but the DM can wing it). But even though you might be in a place where pearls are now bought, sold, or traded for even a hundredth of their "intrinsic" value - they retain that value as far as the game's rules are concerned.

Answer 3

Stuff has intrinsic value so that the game's playable

Questions have long been raised about, for example, buying from another PC for 100 gp a pearl that has an inherent value of 5 gp and using that 100-gp 5-gp pearl to fuel an identify spell. This issue isn't unique to dnd-5e: This kind of fuzzy economics has existed since the game's inception. For example, even the adnd version of the spell identify required—without commentary—a pearl "of at least 100 g. p. value" (Player's Handbook (1978) 66), and the dnd-3e-inspired Order of the Stick Web comic has this brilliant first-panel takedown of the whole process.

I've never known a DM to say that using an item that possesses less than the necessary inherent worth but that the individual has paid through the nose for nonetheless satisfies the item's status as material component possessing the appropriate inherent worth. That is, in the question's example, in this DM's campaigns—and, I suspect, most DM's campaigns—a PC that pays 100 gp for a 20-gp pearl still wouldn't be able to use that pearl as identify fuel.

In short, having things worth a certain amount is a simplification for playability rather than, like, a stealth commentary on contemporary economics. It can be argued that a carefully thought-through full-blown economic model just isn't necessary—even if it would be convenient to have—in a heroic fantasy game about killing monsters and taking their stuff. (By the way, this reader is now interested in a role-playing game wherein the PCs are renegade adventuring stock traders—that sounds like an awesome read.)

If a player needs to know why the 5-gp pearl that he just bought from his buddy for 100 gp is now not technically worth 100 gp—because things are worth what folks will pay for them, after all—, try to explain that even though that player's PC made a bad purchase, that doesn't change how much something is worth generally. After all, one dude overpaying for a rusty clunker doesn't change the prices of all the cars on the lot nor does it change how much cash he'll get as the seller of that rusty clunker from even the average buyer. His folly isn't everyone's folly.

With that in mind, the question asks…

[Is] there's any way to make an object worthless in terms of commerce (so that no-one would want to buy, say, this specific pearl) but at the same time have it still be valid for identify[?] This is so that an item, once acquired, isn't something that can just be flogged [i.e. sold], but something that only has the singular use of being for that exact spell.

Short of something specifically being done to change an item's value, nothing change an item's value. Presumably, if the DM's campaign includes a strong economic model (and most don't), supply and demand may see the DM may lower or raise the sale prices of items possessing intrinsic values, but that doesn't change such items' intrinsic values. The DM's just added market forces to the campaign. And, were those market forces to exist, it would be up to the PC to determine through play how to manipulate those market forces.

Answer 4

A feasible pearl is worth 100gp

A pearl of the quality (size, shape, purity, color, etc) necessary to cast the spell is typically worth at least 100gp. Whether you can find one for exactly that price is another thing entirely.

Value comes from demand. Demand exists because something is useful or pretty

As for whether a pearl could loose value but still be functional, ask yourself this: How much would another spellcaster be willing to pay for a slightly damaged pearl that can still substitute for a 100gp pearl? Your GM may decide that the 100gp pearl itself is already a chipped version just barely meeting the requirements. Perhaps a really nice-looking one would cost you 200gp because any self-respecting Wizard uses a pretty pearl.

Answer 5

You have to remember that D&D is an abstraction of "reality". Just like HP are a basic abstraction metric used to track ... damage, fatigue, loss of morale from near-misses, etc, etc... GP used to track spell-component value is also a basic abstraction.

A 100GP pearl is just saying that the pearl meets "time and quality" expectations for the spell. In the game's reality, maybe these pearls that can be used for an identify spell were washed in the tears of a dragon and soaked in the rays of a full moon for a year. Who knows. All we know is that they're 100GP, which means there's something pretty special about them.

Also, while we can try to apply real-world concepts like economic supply and demand (pearls in one town may be 90GP while in another town they're 110GP, or low-quality vs. high-quality has a range of +/- 50GP or something...) ... again, you can BS by saying that maybe someone in one town found a way to prep pearls for the spell a certain way, but a person in another town found another way to prep them ... and while both methods may be different.. they both end up creating 100GP pearls that let the spell work.

If you think about it, spells are a lot like math in that they have been researched by magicians and they found different ways to get the same result. Just like 1+2 = 3 and 1+1+1 = 3, some magician may have found prepping pearls a certain way worked for the Identify spell.. but you have to then use them a very specific way. Meanwhile a different magician also studying pearls found another way to prepare them and use in a different fashion .. but, again, the end-result was the Identify spell working.

This is why you shouldn't dissect the abstraction of D&D too much, b/c once you start questioning it or trying to shoe-horn real-world concepts into it to analyze it in more detail, you can start to poke holes in it if you want. But, since the rules are an abstraction, you can then come up with reasons why it SHOULD be the way it is.

EG: people have argued over the concept of HP for a long time.. is it physical damage, is it fatigue, and if it's real damage it should take a long time to heal, but if it's fatigue it should heal fast.. etc, etc. The bottomline is.. don't over-analyze it. It's just a game mechanic used to regulate play.

Same with 100GP pearls needed for Identify spell. It's just an abstract game concept used to keep munchkin players from going "well, I'm gonna start a pearl farm, and it's real cheap to raise them, I calculate about 5GP/pearl.. and I'll sell them for 100GP, so that's a 95GP profit/pearl!" Um.. no. We have no idea what goes into prepping the pearls to make them useable in the Identify spell. (Some spells will say how the reagents are used, eg: oil is rubbed on something to do such-n-such). But, as I said earlier, we have no clue if a spell reagent had to go through certain periods of consecration, ritual blessing, etc, etc. All of this is abstraction. The GM can fill in the gaps to add flair via story-telling, but all of it is just abstraction to justify pearls costing 100GP being the ones useable for the spell.

I've played in some games where the GM takes this concept and goes a step further by letting players buy up skill in "reagent preparation". Because, let's face it, stockpiling an MU's reagents can get expensive. So, characters that had enough skill in this could start to find and prep reagents themselves as they found them while exploring.. saving the cost of having to go to "bob's discount reagents emporium". Because, after all, SOMEONE had to figure out how to prep the reagents in the first place, so it makes sense that it's a skill that perhaps magic-users can acquire and develop. But, all this did was work as part of the abstraction. An MU that found some pearls in water that would normally go for 50GP each knows the exact method of preparation to use them for Identify spell... what that method is.. who knows. All we know is that the time and effort they spend in prepping them adds another 50GP value to the pearls and makes them "100GP pearls that can be used in the Idenitfy spell". And, with that, the MU could then sell them as reagents for magic instead of just normal pearls.

Beacuse you have to figure in the world of D&D.. there's probably shady back-alley reagent dealers trying to hock shoddy reagents onto MU's. How do you know the pearls you're buying can be used for the Identify spell? You don't unless a) you have skill in identifying properly prepared reagents, b) you use the reagent and .. oops, it fizzles.

To solve all this, I've played in some groups where they just ignore reagents save for really high-level spells. The fact that MU's are limited to using certain number of spells per day is often restriction enough. If an MU wants to toss fireballs, then they can up to their max spell cap for that level. But, having to waste time seeing if they're pack-ratting all the reagents to cast it.. that just adds overhead to game play.. it slows things down. And you end up with players having to write out huge inventory lists to manage all that junk. It's boring. Those games also ignored food and water, because they wanted to focus on heroism, not "did we pack enough rations to last the entire dungeon? No... ugh.. we have to hike back to town." That's great in a CRPG, but it slows table-top down.