£500 (plus £15 for postage) could potentially get you my Schwinn 4 Banger in a 17" flavour?
I've never really thought about selling it complete, but I paid £450 for it and then fitted it with some Maverick SC32s and better wheels (XC717s on Maverick / Hope Bulb Hubs).
The Mavericks have recently had a full strip and service too, at a cost of £130. So now they're absolutely perfect.
As I said, I've never really thought about selling it complete but who knows