thats not exactly a fair comparison. if, however GM actually made the berger zl1 cars as a factory car; in 2002 with the big motor package and c5r option. which I think was selling for 100k+ when new, maybe in time they would be worth more than the original zl1. its all about what the people that have the big bucks care to spend it on.
look at the early "fuelie" vette's. they get big money. a 57 fuelie convertible is worth around 107K-237K on BJ. a regular carbed car, under 100. yes its rare, but it was so because in its day it was expensive to buy IE technology.
sometimes what makes them rare used to be options that were too pricey in its time to be popular. look at all the 40's and 50's cars that had unique stuff. power folding tops, pushbutton shift on the dash, funky moonroofs, crazy stuff that most poeple didn't want to pay for.
people will pay more for technology that an automaker "showcases" in a car. maybe, lol.