The only reason I see one going for that high would be if a company happened to need one desperately. The other option would be if it happened to be worth collecting for some reason (famous owner, first off the line, something like that). That number seems extremely sketchy considering I can get a brand new full rackmount server for less than that if I shopped around. As for how much I'd ask, probably $50-75 USD. Also in case you need a little information about the specs, they can be found Macintosh Centris 650 Specs @ EveryMac.com