Very true but the huge difference is this - a lot of the Silver Age keys that have jumped in price are of iconic characters a la Black Panther, Silver Surfer etc while the Bronze Age keys that are getting stupid prices are of 2nd tier ‘who-cares’ characters mostly - yes there are exceptions to this. And let’s not forget there are less copies of the Silver Age keys in higher grades than the Bronze Age keys. I feel a huge bubble is coming on these Bronze Age keys and those buying into these high prices may in time be left w deep regrets. Time will tell...
Except that the number of collectors has definitely increased, and of course, the size of the hype-machine.