"Rare" is not directly proportional to "valuable" or "collectible"... In other words, the car has to carry the water to a certain extent...

Can't tell you how many times I cringe when I overhear stuff at car shows like, "Yep, it's rare, one of only 213 '64 SS Impalas built with the straight-six and 2-speed powerglide on the column...., and of those, mine is the only [beep]-green with cow-patty interior from the factory... I figure she'll go high at Barrett...."