As has been said many times, the phenomenon of buying an old car and then watch it rise in value substantially over a short period of time is not normal.
Historically I have bought a car, run it, maintained it, enjoyed it!, then perhaps sold it a few years later and at best got my original purchase price back.
This used to allow me to plan and save for the next car I wanted, on the assumption that I had an idea of what I would be paying for the next car I fancied a year or two before I bought it.
That went out of the window five years ago, and has prevented me buying certain cars I really wanted which have became part of iivestment portfolios, no longer able to be enjoyed by the majority of enthusiasts.
I for one would welcome a return to the norm, which would require a major correction in values, and then watch the portfolio managers dump stock into the market.
It's chicken and egg as to who moves first.
It will/is happening. I sold a highly sought after low volume Italian car a couple of months ago, which I had bought seven years ago. In order to get a sale I ended up accepting about 30% less than the current perceived/advertised values. I was still happy, but it reinforced my view.
Just my opinion.......