Thanks again everyone for your responses. Thought I'd post an update..
I went yesterday to look at it again and talk to the owner. It runs great, has no bondo in it anywhere, (metal was replaced in spots), and has front and rear disc brakes. He said the master cylinder needs replaced because of a problem getting fluid to the rear brakes.
He said the absolute lowest he would go is $8500, and that he has 15k in the truck. I didn't drive it, but the interior really is shot.. and I noticed it was running with no key in the ignition, so that's shot too. All electrical works.
I guess I should just wait and see if the price comes down at all? I told him I was looking at a couple trucks online in the 6500 range, which I've seen, but that isn't entirely true. Still have no idea what I should do here. Keep looking?