The SPF is a replica so lets be honest - no matter what, a numbers matching Cuda, Vette or Mustang etc with the right trim or options package is going to command the money & in my mind many deserve that distinction. Period correct production cars, rare in numbers are going to set the bar for everything else that rolls across the block and it appears that is what most BJ attendee's are after. It's hard to sway the "kitcar" mentality of a lot of people, no matter how detailed or true to the original car.
Had the SPF GT40's (as an example) been built as "limited edition" of say 50 cars only, to "spec" then maybe the supply/demand might warrant bigger dollars but I think we are comparing apples to oranges.
Enjoy your 40 because they are all beautiful in my book - who cares what the auction brings.
Chris