I got a bunch of the X-Men number ones/zeroes back in the 90s thinking they would be valuable and they're barely worth the paper they are printed on. I also have a Spawn #1 that I thought would go up in value, and I'd be lucky if I could get $10 for it. However, I have a valid excuse for my actions, seeing as how I was nine or ten at the time of the afore mentioned purchases and never thought I was investing in gold or real estate.
Thinking way back to '86, the indie comic "The Realm," the D&D-inspired (and probably plotted with the aid of multi-sided dice) fantasy with early Guy Davis art, was considered HOT!!! and Ward Batty was selling an issue of #1 for $50 at the Atlanta Fantasy Fair huckster room. Of course the only issue of that comic with any value is #4, thanks to the first appearance of Vince Locke's "Deadworld" (which perhaps inspired "The Walking Dead").