assuming it's in exactly the same condition, I don't think it's poor form to think I'll sell it for roughly the same price.

See that is part of the problem

1) When we (collectors, mostly) buy machines and sell them again often they are looked after well and in better shape, for many of us, than when we bought them and we should hope to get our money back. The problem for non collectors who never bother to learn how to work on the machines, and that is fine if they just want to play them, but they often like this one, end up very messy and obviously not 'loved' in the way you would that classic mustang.. At that point they should accept they are going to lose money as I need to sink time and money into it just to get it back to what it was when they bought it..

2) Buying off dealers you pay a premium price, especially places like bumper, I don't think it is reasonable to expect that price back when selling privately, both these examples I gave (this and the star trek) were bumper pins, so they paid top dollar, and neither where well looked after IMO