Imagine a campaign where all gemstones need appraising by some (hidden) skill check. The true value is simply hidden from the players. The gem sellers naturally overprice their wares as well, so you can never be truly certain that this diamond you paid 500g for is worth at least the 300g needed for that Revivify.
Imagine a campaign where all gemstones need appraising by some (hidden) skill check. The true value is simply hidden from the players. The gem sellers naturally overprice their wares as well, so you can never be truly certain that this diamond you paid 500g for is worth at least the 300g needed for that Revivify.
(I am aware that this idea is terrible)