I will concede that each post has some merit, but there is one thing that is being overlooked. That is namely that the cars that are changing hands at the upper limits (or at "todays" prices) are being purchased mainly by folks that were teenagers during the heyday of these cars. It is only realistic to assume that younger (like myself early '30's) folks are not investing in a commodity such as classic cars. We might pick up 1 or 2 cars (in my case a LS6), but we are willing to look for the "realistic" priced cars (as evidence by the recent prices on some of the solid lifter cars (not COPOS) that the prices have dropped drastically when offered for sale). Automobiles as investments are great, but only if the market is constantly watched, and most younger investers would much rather invest long term in blue chip stocks than a very narrow commodity such as Yenkos. IMHO what will eventually happen is the folks that appreciate these cars (or any of the hi-po '60's early '70's) AND have the income to support the current prices will die off or loose interest in owning the cars.
Look at the model "T", the 40th Fords, and the '57 Chevy. All were big at one point, but the current prices are no where near record levels. Sure Yenkos/COPO's are rarer overall than these, but the same applies. The cars that are documented original cars, will loose less of the "inflated," value than others, but still they will drop.