As the title suggests, I need to know how to compute the appropriate cost for spells that NPCs provide as services (components included) to the party.
My search has come up with the following:
There is no standard method described in the PHB, DMG, or even the MM (the only books I have). Except in PHB p.159 Spellcasting Services where it is described that:
Hiring someone to cast a relatively common spell of 1st or 2nd level, such as Cure Wounds or Identify, is easy enough in a city or town, and might cost 10 to 50 gp (plus the cost of any expensive material components).
In the Tyranny of Dragons Playtest Player Guide p.11 there was a "Spellcasting Services" table stating:
- Cure wounds (1st level) 10 gp
- Identify 20 gp
- Lesser restoration 40 gp
- Prayer of healing (2nd level) 40 gp
- Remove curse 90 gp
- Speak with dead 90 gp
- Divination 210 gp
- Greater restoration 450 gp
- Raise dead 1,250 gp
The same table states that:
The number of spells available to be cast as a service is limited to a maximum of three per day total, unless otherwise noted.
Based on that (I think) people have come up with the following formula:
Spell Service Cost = Square of the spell level, then multiplied by 10, add double of the consumed material cost, add 10% of nonconsumed material cost.
Found a related conversation for 2-4 on reddit. I have no idea if it's RAW or RAI (Rules As Intended) or just House.
I'm interested on a RAW answer; failing that, I'll take a RAI (Rules As Intended) instead.