This is actually accomplish able with events. If you notice, on pokemon, there's a limit of (what the devil was it...) 20? items in one room. So, what you should do is make 20 dummy events. From there, you'd have to set up a system (through eventing, of course) of variables and switches to make it so that when you place an item, that item remains there, and once you get to 20 items, you need to remove items before you can place more. To remember the event positions, just set up a variable storage for that, 1 variable for the X, 1 variable for the Y.
Edit: I'll work on an example of what I'm talking about. I realized how crazy and confusing I sounded.