I'm GMing for a party that has no casters with spellcraft (crazy I know), and needs to pay NPCs to identify magic items for them. Especially potions, which they find en masse. I was surprised that I could find nothing on how much such a service would cost in town. The best I could find was either buy a potion of identify for 50g and try your luck, or pay for spellcasting.
To pay for a cast of identify costs 10g, but it has a target of self, so the shop keeper would be casting it on herself, and then what? Identify the items for free? That doesn't seem right.
Are there any actual rules for this? If not, are there any systems or house rules that have worked well for anyone?