I finally determined what constitues critical mass for my vintage drum collection. I consider eight drum sets to be just the right number to fit comfortably in the room reserved for my drums. I push the envelope by usually having a ninth set for trade material (almost always a Ludwig). Why Ludwig for my trade bait? Because more people like that brand than any other USA vintage drum brand, and I don't really like them. I have five or six extra snare drums, about twenty vintage bass drum pedals, a dozen or so hihat pedals, a dozen or so cymbal stands, enough vintage A Zildjians for four drum sets, and a few large bins of parts, pieces, accessories, and lugs. My wife and I are thinking about selling the big house, and downsizing. If that happens, I'll probably need to seriously reduce the size of my collection. That is unless we move somewhere with a basement.