First, welcome to Cuda-Challenger. It's the best group of mopar folks on the web. And, any older Barracuda is always a welcome addition here in my opinion.
I'd go to your bank with the closest thing you can find from NADA. They may accept that.
I would ask the owner what kind of maintenance has been done over past few years. By now, I'd have to bet it should be on it's third or fourth set of ball joints and tie rod ends and such. Make sure you try all the lights, windshield wipers, and usual equipment. How soon is it up for inspection? If they are willing, have them pull all 4 wheels off and inspect the brakes to make sure they are working properly, or take it to a service station and have it inspected. I had that done on a car for about $50 a few years ago, on the east coast.
Good luck, and post pictures.
Rick