I totally agree. I was into comics as a kid (in the 90s) , subscribed to Wizard, etc.
I didn't know what AF15 was until I started lurking this board a few weeks ago.
Before I started reading up on the SA Keys, in my mind X-men 1 would be my ultimate "dream book". I mean it honestly still is (even though I somehow want an AF15 , too!)
The popular characters of the present, 10 yrs ago, and 20 yrs ago, should be somewhat a relative driver of future demand. (Especially if we are comparing blue chip characters to blue chip characters... X-men and of course Spidey were big in the 90s... I don't remember any of my 12yo buddies thinking the Fantastic Four were cool!)... just one anecdote but bottom line I consider X-men to be very top tier in terms of mainstream cultural staying power. Would put Batman and Spidey in the same boat.