This is what I'll say about the price. He'd been looking for months. Everything he looked at in the 5-6k range needed rockers, corners, cab supports, work under the battery as well as on the doors. Most had issues with the bed. Most of the 7-8k trucks he'd seen were nicer... looked good at 15'-20' but still had issues. 10k was his max budget for a truck that he was going to immediately do an engine/trans swap on. He wasn't finding any trucks to suit him. Everything was either junk or way nicer and more expensive then what he wanted to pay. The week before he bought this one I'd found a 71 swb chevy that the owner claimed to be rustfree with factory ac (working) and a fresh engine for $7500. He called the owner who told him the truck sold an hour or so after he listed it... and it was a cut down longbed.
So, if you live in a part of the country where there's an abundance of 67-72 gm trucks with zero rust that you can drive home in the 5-6k range... I'm happy for you. But that's not the case where I am. I will say that he was offered 10.5k for it the day after he bought it by a gent that had also been looking for one of these trucks for awhile. My friend would of made a nice profit, but he would of had a hard time replacing it for the same $.
So, now you've heard my roundabout summary of my personal experience with truck pricing in my southeastern region (250 miles of chattanooga tn). You also know how much he could of sold it for and made a tidy $. I guess, I didn't answer your question at all... but you can feel free to do the math in your head. You're probably close.
I'll definitely have some more pictures soon.