Did you run a check on Edmunds or KBB?
Look at autotrader also and see what other OB's of that year and mileage are going for.
You may also want to check out the Yahoo OB group and ask around there Larry III may be able to help ya as well, here's the
Link
My wife drives a 97OB' that has 80 some odd on it right now, I figure if we were to sell I'd be asking for 6-7k.
(edit:Pockets ya beat me too it!)