It works as expected: person who initiates buying/selling with highest Bartering gets best prices, for the whole party--but only in single-player.
In co-op, only one person may speak to an NPC or trade at a time. The other player cannot interact with an NPC while the one is speaking to them or trading. This makes it so in co-op, anyone with less Bartering gets poorer prices, because they must initiate on their own, based on their skill.
Last edited by cilantroll; 02/07/14 05:59 PM.