I think it's a combination of things that factor into extremely high Ebay asking prices. Most of which has already been mentioned.
I would like to add this..... besides ridiculous Ebay/PayPal fees, high shipping costs in place by the 4 big shipping companies..... also consider the drum strippers. I sell on Ebay often. I also buy there. Now, I have some vintage drums that I would like to sell and get a little return on. Not over the top, but a small return for my time and effort that I put into clean up, fixing, and somewhat restoring these drums. I have to say that even though I've blocked MOST of the known culprits/strippers from purchasing my stuff, there are new folks every day waiting around to snatch up that mid 60's Rogers bass drum for the $400+ worth of parts that are on the thing. They lurk on ALL the forums too....
I refuse to let drums go just to see it stripped naked for the parts .
One way besides blocking these people is to list your stuff above and beyond the value of the parts on the drum on the open market. Its getting out of hand. We all need parts but I make it a point to buy anything I might need from a somewhat safe source.
This by no means is an explanation for the $400 ride tom but generally speaking, I think the vintage drum strippers play a big roll in the escalating out of hand prices on somewhat plentiful and not that rare drums.
I may not always get my price on Ebay or the forums , but I will do my best to weed out the folks that have a total disregard for the instrument that I love. I don't buy from them, and I do my best not to let them get a hold of my stuff....kind of a catch 22 ...
Paul