1964 Dart GT & 1965 Barracuda

Barracuda looks like it might have dough in the quarters. Common. I think there are fair to poor patches available....but you'd be paying for work and paint that needs redone.
IMO 5K tops if V8, less if 6. If I'm wrong and the quarters are rock solid and original and it's a v8 car, then 10K maybe, if everything else is good/excellent.
Can't see Dart real good, but is worth less than Barracuda, even if same engine, unless body is more solid. Open the vent boxes (on both cars) near the kick panels and put as much of your arm up in there as you can...feel around the bottom of the "stack" and see if it's rusted out. That's a royal pain to fix....and expensive. Also look for rust or repair on the A pillar. Should be noticeable when entering/exiting car.

I love that body style of T Bird, but unless they are original and mint, thay are not worth anything. I don't know why, but they just aren't. You can get a #2 condition one for about 10K.