Yeah- I see that it is much easier to collect vintage drums than it is vintage guitars. Heck, you can't even touch most vintage guitars from the same time period unless you buy something totally buggered; even then- you pay 'cos it's a vintage guitar.
I suppose it's the fact that you can have 100 guitars in the space that you could have five drum kits is one chief reason why vintage drum kits aren't nearly as popular to collect.
But also, some guys will argue that the best drums built are the ones currently being built. I don't subscribe to that viewpoint, frankly. I will say, however, that this is the best time to buy student kits since the time that student kits were built right alongside the pro kits in the Slingerland, Ludwig, and Gretsch factories. While I am not all that keen on my OCDP kit in many ways- in 1985, $500 got you a used kit (not yet vintage) or a very poor student kit; now, $500 buys you decent quality drum shells, minus stands. You can spend more, but you have to spend 3x as much to get something really nice in new drums.