I bid on Ebay for a job lot of 40 computers and 25 ethernet switches; this was three pallet loads. My plan was to pick them up in the car (maybe three trips), store them in the cupboard under the stairs and look at them one at a time, install Linux on each one, document the memory, disk and ram, and sell them on Ebay as individual computers.
I have no idea if there's a market for fairly serious servers sold secondhand. But it would have been interesting to find out.
Unfortunately, the bidding went up to £300, which was about twice as much as I was willing to pay for such a punt.
It would have been fun though. Computers are the best toy ever invented. I'll look out for any similar sales; it looks like job lots of servers are a regular feature on Ebay.