This is true. Nobody is obligated to price their stuff any particular way. Still, I frequently say that in a just world, every second hand item would be priced at half-retail. By that rule, that lugged Susie on eBay is proof that this is not a just world.
The high-price justification that I've seen from time to time on out-of-production Rivendells is: "Here is a 58cm Rambouillet frame set. Since it's out of production, the only way to get one is to pay for a Custom, and those are $4000 with a two year wait, so I'm asking $3600 and you don't have to wait!"
Pretty iron clad logic there.
Bill Lindsay
El Cerrito, CA