This week my players are heading into the major city and while they're there, will have a chance to buy some scrolls, potions, and two Uncommon magical items. I've already come up with prices, but next up is the question of how to deal with them bartering with the owners.
They haven't bought anything from this city before, so I would assume that all the vendors are neutral (save for one who dislikes everyone) so they'd be at a clean slate. I'd allow movement a bit if they engage in RP to talk to the vendor, learn about them, commiserate with them possibly; that however isn't important now. My question is, how do you handle Relationships with Vendors and DC values for Persuasion? This is what I've got personally:
Relationship Persuasion DC
Against those rolls:
Persuasion Over DC Discount (%)
1-6 -10 7-11 -25 12-19 -50 20+ -75