It's not a case of people not knowing Frirebirds. Production numbers mean nothing as far as value goes. What about an Ambassador Madador? Their numbers are as low as it goes, but nobody wanted them when they were new, and nobody wants them know, if such cars still exist.
The bottom line is that they are not pouplar cars, as in high demand for the cars. BJ auction proved that when they were giving away 69 T/A's for a lot less money than many board members have in their cars.
Because the cars aren't as popular as other cars, the prices are lower, and the prices will never catch up to the Camaro or the goat.