>>10611253The thing that will keep G1 prices up is the same thing that keeps old DC/Marvel first appearance issues and NES games up- the characters continued relevance. Action Comics 1 and Detective comics 27 are still worth millions, and that's not kids who grew up with those first issues buying it. Same if you see the late millenials and zoomers who pay obscene prices for NES/SNES games they at best had secondhand nostalgia for from aftermarket/handmedowns/emulators. 22 year olds buying Ocarina of Time on N64 for $80 were born years after it came out, but they grew up with later games or a port and want the original out of their fandom of it.
With those 60's/70's toys or before, they failed to establish a multigenerational collection. Look at GI Joe, which stopped being relevant past early Millenials. A lot of 60's/70's toys were also one-offs and small lines- the 80's really established these toylines as long running brands and franchises.
Transformers is at least secure for another 20 years in prices given the amount of teenagers online in the fandom. With the current slate of shows and movies bombing though, who knows 20 years after that.