We had the same issue with our 3-man (+NPC) playthrough: the barterer hogs all the cash and "does his thing", while us other two stand around picking our noses, with no oversight or chance of input. Too bad our barterer, as we found out after checking the safe file he passed us in case we wanted to play on after our post-Christmas LAN's end, is also what some would call a min-maxing powergamer with an egotistical streak - not the greatest asset in what is supposed to be a team effort. While my mate and I are equipped mostly in slightly out-leveled greens and the odd blue, Mr. Moneysack just happened to be decked out in pretty much all up-do-date purple, with (of course...) all the skills learned he could ever hope to need. Yeah, great teamwork, that...
In multiplayer, you're at the mercy of the barterer's honesty and integrity - or lack thereof. Suffice to say we have not played with him since. We've started our own two-man game and keep it honest, but the fact that he can't see what I'm doing in that there trade window is still pretty annoying.
