Jeff, the phrase "what are you asking" is commonly taken to mean "how many dollars are you asking for in exchange for your car"....
You'd be hard pressed to get a diagnosis of bad guides WITHOUT dissassembly (and short of catastrophic failure, of course). My thought is that dissassembly would show a tiny crack somewhere, thereby rendering the entire bill an insurable event.
Q45tech- what are the odds something is amiss in the platic guides?
Of course, if not you've just spent 1500+. Perhaps you could work out a deal with the buyer: he gives a deposit, you do the work, if the guides are covered by insurance the deposit goes to the sale price- if not, the deposit goes to the guides. The buyer takes all risk AND all upside. Point being the work is done while it is still your dads and on his warranty.
PS I'm not in the market, just thinking out loud.
Adam