1970 cuda gran coupe??

I am well aware that a 65 will never bring what a 70 will, but for the same token a 65 is holding its value and or going up, while a 70 coming down some? I am not talking about the hemi. I am talking about base models. BTW Where do you find a 70 barracuda, gran coupe, or cuda for $2500 that is not fully rusted out and not usuable?

What info I am looking for is trying to figure out the major problem areas and what will kill a car. Drivable wise and value wise.
Completely mangled or rustic frame rails, completely rusted or mangled you unibodies. The aftermarket only makes so much for these cars. Now if you want to do a challenger, there are brand new challenges bodies available.