Good discussion guys. The primary consideration when the conversation comes around to prices, especially when they go up, is demand has to be there first to bid up the prices. Without demand, prices would remain "soft". With that in mind, I would suggest that two things contribute to the recent (say last 10 years or so) swing in favor of "newer" cars as opposed to the typical old line rods that were largely pre-WWII. One was the guys who had been doing the more traditional bodied cars (regardless of style) were at a point in their lives where they were both interested/motivated to do "something different", and financially more able (kids gone, higher job achievement/pay, mortgage paid, college costs gone, whatever). They fell back on, as mentioned, what they knew in their youth, either as actual owners or wishers. The second group were the somewhat younger guys who never got into traditional earlier cars, but knew muscle well from their youth as well. These folks were/are in their personally stronger financial position, though maybe not as strong as the older guy who might have both kinds of cars in his garage. Both of these enthusiasts are solidly in the over 40 set. As they both "converged" on the muscle market near simultaneously the competition for acquisition tested the limits of supply, driving up prices.

Now the nut of the matter. Sad(?) reality is this group will be dying in the coming years, removing demand from the market. Looking at the numbers, there aren't enough younger guys who will be as interested to maintain a one for one replacement rate, even as those younger guys become more financially viable (assuming they won't be taxed to death to support SSI and medicare, a realistic, unfortunate possibility). Looks to me like those young guys are going to have a very big supply of cars they desire to pick from, and likely at ever dropping prices (to a point). When that will happen (and it won't be a light switch moment, rather a gradually accelerating situation) is wide open for speculation, but it will happen. It's in the numbers.