Much as I like the Trade rules I have an itch for something small and focussed that the characters are involved in - moment to moment - that can be used for specific rare items or slaves. Maybe it could be a minigame in itself almost taking into account:
appropriate proficiencies
Wisdom - ‘oh, but I really want it’, ‘I can’t let them buy it whatever the cost!’
Any ideas ?
It might be interesting to approach that with a simple table to simulate the actions of the NPC bidders, basically a Reaction Roll variation, appropriately modified by PC stats and proficiencies. The PCs would still have agency, but I bet there’d still be a lot of failed WIS rolls (as it were).
I like the idea of making a save to simulate the “desire spiral”, but otherwise I’d prefer just RPing it. Perhaps just a table with modifications for wis and proficiencies if players don’t want to RP it. It could list results all the way from “You fail to win and earn the enmity of another bidder for driving up the price” to “you intimidate the other bidders so much you win the auction for a pittance” or the like.