I bought a transfer case from the seller of that truck, Joel, a few years ago. He's thinning his heard this year. I assume it's because prices are so crazy. He's already sold two similar trucks so far this year. All pieced together "Frankentrucks", but solid and needing paint. He told me in an email that 13 was too many, so some had to go.
Don't count on it, but maybe... The guys who loved these trucks growing up are coming into retirement age. I don't think the market for them is shrinking by any means.
I agree that 10 grand is nuts, but it's certainly worth more then 2-3 being as solid as it is. The two trucks he's sold this year have both started at 10K. I saw one dropped to $7500 before the ad disappeared. I'd bet he's selling them for 7 grand, surely no lower than 5.
I don't know the guy, I just troll MN Craigslist a lot and try to keep tabs on these things. There's another Squarebody guy with a ton of parts and trucks in Princeton, MN, but I don't even bother communicating with him based on his absurd asking prices.