Better or not...demand for Firebirds due to lower popularity keeps prices "affordable". Chevys have a bigger target market due to familiarity and larger production numbers, exactly the things that reduce rarity. That's why there are more clones than real performance Chevys.

Look at the pricing of an ordinary Mopar...Dart, Satellite...no factory performance engines or rare parts, were never highly desirable when used cars...what makes them go up? The prices on the Hemis and AAR/TA and Six Packs.

Firebirds are following GTOs up the scale.