There's another problem he sounds like you're the first potential
buyer to contact the owner.

The problem with this is, the owner (seller) hasn't yet figured out
his precious baby ain't all that great. He wants top dollar--minus a
few for repairs--from you, the buyer. If you were the 4th buyer to
look at his plane, for instance, there would now be a record of 3
others looking and walking away from the owner's beautiful plane.
About that time the owner starts to figure out he's asking too much
and is willing to lower his price. But given that you're #1, he's got
nothing to lose by trying to get the max--and if you try to tell him
it's not worth that much, you're insulting him and his plane.

I went through this exact scenario more than once when I was looking
for an Ercoupe. Using the FAA database, I wrote owners in
N. Calif. if they wanted to sell--thus I was often the first person to
talk to these guys about selling. Most wanted too much for runout
engines, hangar queens, etc. Finally found one in good shape at a
reasonable price--I paid his asking price w/o negotiation, since by
now I knew it was reasonable.