The Protection from Evil and Good spell has a material component of
holy water or powdered silver and iron, which the spell consumes
So, to make use of this spell we have to spend holy water (or powdered silver and iron, but I'll come back to this later), even though it doesn't explicitly state how much unlike many other spells.
For example, Glyph of Warding
incense and powdered diamond worth at least 200 gp, which the spell consumes
25 feet of rope, which the spell consumes
We do have a relevant tweet from Jeremy Crawford.
In practical terms, does that mean a flask of holy water could be reused for multiple castings of the spell?
If a DM was generous and allowed that. Typically, a DM will expect a flask to be used.
And here we've reached our destination, from Holy Water (flask) description:
Cost: 25 gp
Now, given that powdered silver and iron doesn't have it's own position in the equipment's list and it's worth isn't explicitly stated in spell description either, it's price is completely up to DM, varying from 1 cp to infinity, which is ridiculous, to say the least, comparing to the fixed price of Holy Water. Assuming it should be at least of the same price as Holy Water, it leaves us with 25 gp for a one-time use material component for a 1st-level spell.
As it is, there are several 1st-level spells that require consumable material component:
- Ceremony with a cost of 25gp
- Find Familiar with a cost of 10gp
- Snare with unspecified cost (it isn't clear what rope we can or should use)
- Protection from Evil and Good with a cost of 25gp
Now, some might say, that Ceremony is expensive as well, but it also provides wide range of options both for combat and roleplay, while Protection from Evil and Good is hardly applicable to anything other than combat encounters.
Am I missing something or does this spell really cost 25 gp per casting?