What are Longhorns going for?

[nibs]

Hey all, I have a guy that is wanting to sell his 1971 Cheyenne Longhorn, and Im trying to figure out a decent asking price. He is the original owner, and is like 80 years old and just doesnt use it anymore.
Here are some details that I was given.
1971 Cheyenne Longhorn 3/4 ton
-Green w/ white top
-350,(not sure what trans)
-New upholstry, floor mats, steering wheel, wood bed w/ stainless strips
-1 owner, never wrecked
-Includes(but not installed) headliner and glove box.

I am told it runs and drives no problem.
Anyone got an idea of a fair price on something like this? Its a Cali truck, so Im sure there is no rust at all.