That's good advice, but typically good back issues and collected editions are more expensive. You never know if kids or teens will appreciate what you do, or those older stories and art.
Almost everything that I like is circa 1980-2005.
If current comic books weren't so bountiful and boring, it would do a lot for getting pre-20's people into them.
I'm trying to perceive it from a parent's perspective - their budgetary focus isn't on entertainment like mine is. I can buy all the cards, comics, and guns that I want. They can't/won't.