Wow, I would look hard and do some careful investigating before I considered that a fair price.
I had a 1991 Cambria with 454, fuel injection and loaded, with nice interior. It was in good condition and I sold it in 1999 for $25000 and now I have seen them as low as $12000. That was wholesale NADA price at that time. I don't believe anything that old is selling above wholesale at this time.
The 1991 Cambria was almost identical to the Ulrastar and from a distance you had a hard time telling them apart as they used the same front and rear caps. All the cabinets, appliances and furnishings were nearly identical.
There are glut of units in this range. That is low miles and may be in good condition but I would check the market and not go by what a dealer is telling you is a fair price.
Bob
