Those games were out of style???
Well...yeah. For a long time, this stuff was considered junk. You couldn't give it away. JAMMA cabs went for like $50 for fully working games, and they'd toss classics on the burn pile.
Consoles? Fu-ged-abou-dit. Commanded measley prices.
Now that this stuff has come back in style, it's commanding high prices. I only wish I'd gotten into games ten years ago, when I had money, and did nothing except piss it away.