I think there's also some ebay-psychology at work here.
So just a hypothetical situation: some guy has an early 80 Tama kit. He lists them on ebay at more than he bought them for new. They're 25 years old, so they've gotta be "vintage."
Of course, nobody bids.
So he lowers the price by $100.
Same deal. No bids.
All the while hes watching other Tama auctions, and despairing that his kit won't sell. He sees someone list 3 tom lugs, and someone else bids $10 each for them.
The seller looks at his kit and the lightbulb goes on - "look at that, I've got at least 50 of those...that $500 is better than nothing."
So he lists a couple...he gets $10 for 'em. But now the market for old Tama lugs is glutted...and he's back where he started. He's asking too much for the remaining lugs...and the whole kit is now incomplete, so he can't flip it as a whole either. He's kinda committed to parting it out, one way or another.
You see the same thing in consoles - the whole doesn't sell, so they start selling off strips...and then after 6 months, you see the console listed again, now sporting a buck-tooth grin.
Not every console strip is a 1073
...not every old drum is a round-badge.