In this crap market, I can no longer buy, overhaul, and sell 'em for a $100+ profit. So if I find one with something I want for myself, like a Super Record rear derailleur, I may buy if I think I can easily part out the rest for a small profit. This gets me my wrenching/polishing/truing fix and something sweet for one of my keepers.
So, bottom feeder, I guess.