Value of a '70 GMC C30 Longhorn?

[Marauder_Pilot]

I found a SRW C30 Longhorn locally and took a look at it.

Good running condition, runs and drives just fine. Has a 402 with a new carb, automatic trans, straight pipes and a 9-foot that the owner kept stressing that it was 'really rare, maybe 500 left in the world'. (Whether that's true or not, I really don't consider 500 that rare, but whatever)

Minimal rust, the only real rust spots I could find were the running guards and a little bit where the chrome flaked off the grille. Paint is original, but in good condition, and interior is, except for some ripped vinyl on the bench seat, minty condition. Really nice overall, runs already but plenty of room for improvement and modification.

Owner wants $6500 OBO Canadian for it. Reasonable price?