Kirk's reference to the NADA pricing website is a good place to start, with the knowledge that the prices given to the public are somewhat higher that those given to N.A.D.A. member dealers. Also, I understand they are somewhat higher than Kelly Blue Book prices as used by banks, Etc.
Lotta good advice above. I also am wary of a unit 3 yrs old (could have been built in late 2002) with this mileage on it. There is a thing called "lot rot" i.e. inactivity which accelerates deterioration of RV's.
3000 miles is used no matter what they say. Don't pay any more than used value for it, and check the warranty provided/left. NADA (link above) should give you a good target value, and the dealer should be eager to unload a 2 to 3 year old elephant...
Thanks everyone for the input. I ran the book value, it can in at $276,000.00 in good condition. Since I posted the first eamil the dealer has dropped the price below $ 275,000.00 and has offered to supply new coach warranty. I've done my homework on the dealership (BBB and such)and they come in with high marks for service after the sale. Guess I'll buy extended warranty and make the plunge.
Thank you all and I'll be back with, How-To-Questions, as I become a, RVer.