Part of the reason muscle cars sell for so much is the people buying them now wanted one when they were in high school and couldn't have one. These cars also have more of a mind share in the culture because they were mass marketed.

The VX was always a specialty and never garnered the reputation when it was new that people really remember it. There is also a huge difference between a car 43 years old and one barely 10 years old. In 1979 or 80 I doubt a 69 Firebird was worth all that much. You can still probably find a few well worn ones pretty cheap, that's where all of the new builds come from. It would be interesting to plot the price of a car like that over time and see when they stopped depreciating and started up. I wonder what a VX will be worth in 2043?

I never liked the Firebird's much anyway. I was always more partial to the 66/67 GTOs