People are still thinking these are worth mega bucks (and some are) if they are restored, finished and ready to go.
Or they are the most desirable model and in reasonable condition and basically complete.
Most of the time they are overpriced junkers in need of major restoration and not worth the money being asked.

Like all cars there is only a certain market. At the moment '70's cars are a little more desirable because this generation are coming through and trying to buy "their" memories.
This inflates prices, but is only relatively short lived. I have seen the same thing happen with early sixties and then late sixties cars. You watch them peak in price and then settle.

Just understand, it will soon be the '80's crap that is hot and wanted and the '70's stuff will cool off on price as the amount of people willing and wanting fades.

It is the memories of what they had or what they wanted and couldn't afford in the day that they are chasing. Not many actually want to or are capable of restoring.