1977 Ford F-250 Extended Cab?

I am selling a Ford F-250 Extended Cab, long box (trailer speacial) automatic 2 wheel drive . It has a ford 460, everything is original under the hood. It has about 198,000 miles on it. motor and havent been replaced. interior is real nice, bench seat in the back. It sits on 33" firestones with 80% tread on them and has eagle alloy rims. motor is a little weak but like i said it is all original very nice body for the year. i would like to know what a good asking price would be for it, thanks