I agree with Mr Popo. Video games are very different from baseball cards as a commodity, enough so as to make comparisons highly fallacious. But beyond that, I don't think a "collapse" or "crash" is the most likely way of decline.
The way I see it, this is how and why the prices of retro games have changed over time:
1) Original games run into obsolescene. Prices drop as the product ends its original life cycle.
2) Stock is cleared, leading to extremely cheap prices and plentiful second hand opportunities. Old games are seen as worthless and no distinction is made between different titles
Big one: Emulation becomes solidified.
This took place in the early 2000s, games were extremely cheap back then. People were buying full arcade cabinets in cleareance for 50$ or less because they were seen as bulky garbage.
I think that, culturally, many gamers still think of these prices as what should be "normal".
3) Perception of retro games' value and quality turn around. They begin to be seen as having intrinsic value, retro gaming communities as we know form and opinions shift. First "guides" pop up.
I think this era is when many of us got into retro gaming or got serious about it.
4) Members of retro gaming communities get older, get jobs and can afford to invest more into their hobbies. Moderately experienced members move onto more hardcore stuff, increasing prices. Retro games hit big in the gaming mainstream, bringing new retro game fans. Content about retro gaming becomes big
This is where we are now though we are moving into a new era where people are very organized, to the point of seeking increasingly involved areas of the hobby (Professional CRTs, for example) and even creating specific hardware and software (OSSC, CRT_Emudriver, MAME variants, etc.)
I think this is very different than baseball cards which were simply printed in enormous quantities and which have no appeal beyond an extreme, dying niche. I mean, it's a niche inside a niche, it's not just people who collect baseball cards, it's people who collect baseball cards that feature people who haven't been in the sport in decades.
Your hypothesis are a bit more complex so I'm going to reply on the post below
