Fair price

There is a mustang II running around town, it has about a ten footer red and black paint job, the motor is stock 302 and C-4 auto the only upgrade is dual exhaust with chrome tips out the back.
Now my question is what would be a fair price for this car?
Don't worry I am not a II hater I like all mustangs and always thought the II's would make a real sleeper with a stout small block and gears, and I figured they handle good as well.
 
Or it could be worth it's weight in scrap.

Local kid put lots of work into his II, looked good until I looked underneath.

I would have been afraid to drive it around the yard.