I think it has to do with the merchant restocking and better items thing. I pick-pocketed over servral hundred thousand gold worth of arrows and and over a hundred health poitons. I killed one later on and he drop all the stuff you could trade for/pick-pocket. I am glad I put all my points into pick-pocketing, I stole enough potions to let my DK tank, and enough to unlearn my DKs weapon skills everytime I find another weapon of a diffrent type!
