I'll say what I say every time this gets posted.
Not happening anytime soon. Prices will go down when the games, or more likely the consoles are non-functional. People will get scared as their games begin to break, or frustrated their consoles keep breaking, and sell them.
When games and consoles begin to get to the point where a functional console/game is a rare find, then prices will drop. But they will drop just like they rose. Atari, NES, SNES, etc from that gen will go down first as they begin to break. But when that happens PS3 collecting will probably be all the rage, so you will be fucked there.
Like many people here, I've began to realize collecting is stupid AF. It took a cleaning and testing of my MVS library earlier this year to finally figure this out. I take great care of my games, but still they were filthy, leaking, and some had exposed traces. That was my ticket to GTFO the hobby. So this Winter I'm selling all my stuff I can everdrive, and completely dropping out of Saturn because it's ridiculous. My stuff will be long gone before it breaks, and I will be way ahead, many many thousands ahead of my investment since 1997 when I started buying NES games with my lunch money at the flea market on the weekends.
Do yourself a favor. Quit researching game prices, and use that time to play games. The collecting of game consumes more time than the playing of game when you get too deep. I've been there. Lots of us have. Life to short to collect. Just play while you still can.
Consoles becoming non-functional may not be a big issue with the appearance of new FPGA consoles. The Retro AVS is pretty affordable and has been well received. Not saying one way or the other what effect they will have on game prices, but it's nice to know options will continue to exist to play on industinguishable-from-real hardware.
Agree on that last point. At some point you gotta stop buying shit and obsessing about your setup, and just sit down and play what you have.