I got a '74 coupe a few years back, added a '75 2.7 engine (car and drivetrain from Pelicanheads) and painted the car Mexico Blue.
Because of a move and investment in a new company, I had to sell the car and after a fair amount of time advertising and promoting it (with full disclosure), sold it @ under $9K -- about what I had in it.
The new owner had it for a year and a half, lowered it, put better wheels on it (probably other stuff, too) and recently sold it.
Within 12 hours it ended up on eBay with a "story" and is now bid at $24K. That's a lot to pay for a gold '74 sportomatic sunroof car with some 'de-contenting' and a pretty color... but that's the marketplace.
Link:
http://tinyurl.com/5rszjl
I guess as a marketing guy, I shouldn't be surprised, but I could never bring myself to promote the car as a "210 HP" "Street legal RSR."