31 k Mile 77 Aspen 318 A/C

So we take the son's Mustang in for regular maintenance. I pull up to give him a ride home and I see a 77 Aspen 4-door. I go up to it and it looks real clean, then the sticker in the window is 31,1xx miles and the chrome and interior are perfect. Body is real nice and no rust anywhere even around the seams. It has a 318 with A/C and manual door locks and windows. The seats had no holes and the gauge cluster looked real nice. Even had the owner's manual in the trunk. Trunk looked clean and no holes in it. It looks like it was recently repainted. The alternator looked like it was recently replaced.

The A/C and radio didn't work. The suspension felt a little "saggy" on the test drive.

They were asking a quite a bit of money for it and wouldn't go down very much.

What do you think this is worth?