[RickM]

Why are you factoring in Valve guides? I see no evidence of this car needing them.

Also, while not regulary changing the oil is not desirable (at all) in a car used this little, yet brought to operating temperature regularly, I really doubt it did substancial damage. Yes lower the price but I don't think it merits by Big $$$.....well what's considered big $$$. If you end up with the car do 2 or 3 back-to-back oil/filter changes.

In any case offer as little as possible....you always want to start low and go from there.