I don't know, I think being an RPG merchant would be an almost biblical curse. I'd have these guys coming up to me, turning over garbage like infected slime pustules looted from monsters, and taking my gold and valaubles away for it. I mean it's beyond me why anyone in business would want some of this stuff, and a goodly amount of it is actually gross. "Hey dude, while hunting down rat tails, I cut out 40 tumorous bladders, give me money for them!".
That said I'd probably sell magic bags, in absolutly huge sizes, that secretly teleport their contents to me every 48 hours or something. Somewhere out there would be adventurers screaming "OmG HaXxORs gOt inTo mY sTuFF" and many petitions, but in reality I, the humble in game merchant would have their loot and be putting it up on the auction house to sell back to them. Yesssss. 36 slot bags, only 50 coppers! nono that isn't a misprint... it was intended that way!".
I might also consider being a ladies only Gigolo, you know most female PCs in these things are absolutly gorgeous so you know... hard job, but someone has to do it!
