Once a vehicle reaches collector status, strange things can happen.
I worked in a restoration shop about 30 years ago, where we specialized in Mustangs, Shelbys and other classic Fords. Around 1980, Mustangs suddenly became very 'hot' and prices skyrocketed. We had customers come into the shop who had paid $20,000 for a 'restored' '66 convertible, and were shocked to learn that the car was unsafe to drive - the frame rails were so rusty. Because these cars were unit construction, a repair like this meant cutting out the rusty bits and welding in new integral frame rails. I remember one customer so upset (he thought we were pulling a fast one on him) he stormed out of the shop and jumped into his car - only to have his seat fall right through to the ground!
After a couple years of wild speculation, prices plummeted and people became much more informed about what was 'correct' or 'incorrect'.
Shelby Mustangs became so valuable, more than one was resurrected by pulling a Mustang apart, installing the Shelby bits, including the VIN plate, and passed off as 'restored'.
I also can't get over the discrepancy between 289 Cobras and Sunbeam Tigers. For decades, Cobras were trading at 10 times the price of a Tiger, yet both were small British sports cars with Ford V8s, and properly tuned, were pretty comparable in performance. Doesn't matter much to me, though, I can't even afford a '66 Mustang, much less a Tiger
Now, when I go to a classic car meet, I can't get over how 'incorrect' many of these early Mustangs are, and how much they're selling for. It seems everybody forgot those lessons of the '80s.
In my mind, the ideal value of a classic vehicle should be a little less than the cost of restoration, if it is 'correct'.