From what I have seen lately, prices are declining... Don't assume its a POS (certainly could be) a lot of 60/70's muscle is not selling nearly as strongly has it has in the past. Fact is that the enthusiasts for these cars is not a growing community, it is aging out and become much more selective in what it pays top dollar for. While the "gold rush" of high muscle car prices were directly responsible for a lot of good things such as the development and sales of good restoration parts it also was directly responsible for the flooding of the market of anything and everything being build/painted and brought to auction. So there are a lot of mediocre cars out there and a lot of good cars but the buyers are not there in the same numbers with the same amount of cash to throw around.
The big money is going towards rare/unique cars as well as very well done customs/restomods. Many of the popular car shows are singing the praises of restomods/customs and this is showing up at the auctions.
You don't have to like it but that is where it is going.