1970 Dodge Coronet 500 barnfind

He's only had it for 44 years so he just might be a tad emotionally attached to it.
You need to decide if you are interested in it and can make the effort and investment ( that as others have said you won't get back).
But it is a unique opportunity to get a cool vintage car from the original owner.
Don't expect it to be cheap and I think interms of first getting it on the road: new tires, batteries, brakes, maybe gas tank, etc...