i also watched The Shepherd last night and kathryn talks about the windmill they had on their front lawn that david hated, and then it ends up in Golds shop. so my theory is that everything thats in his shop is stuff he's collected/made deals from Storybrooke citizens. like the genies lamp for instance, lets say that Sidney had it in his house but no longer wanted it, he sold it to Gold. i know a lot of us were thinking all his items in the shop had just magically gotten there from the curse, but i don't think so.