impact of modern muscle cars on the old car market

The one thing classic cars of the 60s and 70s have over the newer cars is ease of modifications.

I agree with the above. I think one big thing that has made our A bodies so popular, and not just the lower cost to get into, is the fact so many A's were born slant and 318, sure there were many 340's cars, and some factory big blocks, 67-9,..... but compared to say B bodies, tons of A are still found ripe for resto or modifying, owners choice. The SB and slant B bodies are not near so plentiful, and they will demand more $ for the guy wanting to build the clone. I have owned many 68- 9 rodrunners/bees, and I have had the hots for another quite a while. But I refuse to give $3-4-5000 for a true 69 383 runner, project that need everything just to finish it and tell myself, because it was born a 383 69 runner, it is worth $25-30000 to someone. Not building it to sell, I just soon give $1000 for the same turd that was born a satellite! and go from there!!!!! LOL
That satellite I would build to RR specs, finished would bring probably half what the real deal would bring.. So being that I have NO ego and would be happy with the " wanna be" runner, that would be my route.
Prices and what people think about the subject is interesting to me. But being I am not buying, selling... just have my own "toys" it is a mute point. I pay what I think a project car is worth (to me) and if I don't find one for that I do not buy. But the subject of what is it worth? is still interesting.
We tend to see so little "sales results" on this site, FB or whatever to get a good handle on what is something worth. example: I have a neighbor that has a 72 400 charger for sale at $4500, Not restored, all there, decent car and driver.... I figure it is worth $2500, if it sells and he tells me what he really got, not BS, then I have one sale to go by. But one sale does not make the market!!