I can speak to this article just a bit. It is not that auction houses are inflating prices. Parts to rebuild these cars have risen to keep in pace with the price of the same parts used on new assembly line vehicles. In most cases they are more expensive because they are produced in smaller quantities.
I am rebuilding a '71 Chevelle. I already have almost $20,000.00 in it and I have not touched the interior or paint and body. It will easily cost $35,000.00 to complete.
When you upgrade to modern components they way I have, and the way most auto restoration houses would, it gets expensive quick.
Front end work: Includes upgraded 4W disc brake conversion, Hotchkis total vehicle suspension system,
Crate engine and 700R4 transmission upgrade
Magnaflow dual exhaust
Shot under rear with new suspension and rebuilt differential:
I am now reassembling the engine and will get it running before I do anything else. Then it's off to paint and body.
My point: Rebuilding a classic is very expensive. Paying $40K to $50K for a completely restored well done example is a good deal. What you should not do is pay tens of thousands of dollars for one in un-restored original condition. Finding one in that condition is great if you want to restore one, but limit what you pay for it to less than $10,000.