I would bet that of all collector-to-collector vintage
computer deals out
there, 9 of 10 are done on Ebay.
No way, first off most collectors selliing stuff, bought it via some other
transaction other than ebay.
OTOH if I had some choice bit like an Altair to sell, ebay sounds right to me.
OTOOH I do sell a fair amount of stuff for old computers, and I would say
its about half and half ebay vs support lists. As a practical matter the
ebay sales almost always are better transactions, smoother, faster etc.