1970 Dodge Dart Value

Landon,
I would wait about 10 days, approach him and tell him that you have a budget of, say $2000 (or whatever you want to offer) and let him know that this is a firm CASH offer. Have a note card with your contact info.
I got a $7500 asking price car for $6000 back when it was a seller's market. I made my offer, gave him my contact info. Two weeks later he called with a $6500 price, I said I still had $6000 cash, he said sold.
The value of any of these old cars is what someone is willing pay, not what someone will ask. He needs to know what you are willing to pay.
David