All depends on how the private owner looked after the machine.
TAF - $4500 - $5500
ToM - $4000 - $4500
ST TNG - $3500 - $4000
They usually fetch lower prices on eBay because they are usually tired and unshopped. Higher at dealers because they are usually shopped and have most of the upgrades etc done to ensure reliability (well only some of them go the full extent).
