You people are funny. But I see the logic in the concept. Its more of a; Set up shop and keep the vendor supplied with those items= make caps.
All in all a sound idea. The problem is, how would you balance the flow of cash? relying on npc's to randomly purchase these items. Yet if they use them they would probably spaz out and you would lose your customers from them going homicidal and getting the whole cell in an uproar.....I condone this idea for a mod very much....If nothing else. It will make me laugh. XP
My idea, is that not one actually ever buys anything, Its to make a container that a NPC has set to sell items out of, that way a vendor can be filled with what ever items you put into the container. Then just randomly remove items from the container from now in then, adding probable random amounts of cash, That way you get the feel of someone bargaining for your items.
EDIT
Just thought of some draw backs, you wouldn't be able to display any of your items for sale, I wonder if I could make a two containers one you put everything into and another the duplicates whats in the first container, so when you deposit an item you may go to the other container and use the items out of there for sale, But then I would have to give them no value and make them really heavy. Which I don't think I can do in code. Small little problem I am going to have to figure out. unless I could trust someone not to be using it over powering to get duplicate items then I could just do the duplicate item idea.