hmmm....you're probably not going to get more than $2,000...if that. We paid $2,500 for mine, and it's body was fine....interior needed a little work, as did the chassis and tranny. But, it was fine other than that. I looked at a real horrible one for $1,800....you could start with that and let the people tell you what they'd pay.
The best price is the lowest price someone is will to sell it to you for. Now this may seem like a smart *** answer but that is not the intent. There is no NADA, Kelly Blue Book, or Black Book on old wore out 65 Fords. They are worth exactly what a restorer is willing to pay.