One shocker is how much old CRT are worth especially big high end ones. People are interested in those old computers. But can't find a matching screen.
If you're willing to slum it with 1024x768, you can pick one up for $20-$40. If you're looking to buy a Trinitron then be prepared to spend quite a bit unless you're buying from someone who has no clue what it is.
With the launch of the new ARM MacBooks and Mac Mini, how long do you believe it will be before the last Intel models such as the 2020 MBA and MBP models will start to become sought after much like the 2005 PowerPC Macs have become to collectors and those looking for unique capabilities that Intel Macs have such as being able to run Windows?
That's a hard question, because PPC Macs aren't valuable simply because they had a different architecture (though that does factor in!) They're valued because of the circumstances around them. I bought my iMac G3 a few months ago because I remember seeing them at school and on ads on TV and thinking they were so cool! It's the computer that saved Apple too, it's a sign of the triumphant return of Steve Jobs, it was unlike any other computer at the time, the list goes on. Look what Apple was at the time, the little guy fighting it out against the big giants of the industry, the guys who revolutionized the MP3 player with the iPod. It's just as much a sign of Apple nostalgia as it is a machine. With the Intel transition PPC died in the consumer market too, leaving some old games and software stranded, so some people got that nostalgic itch and kept those old machines around. I've even heard some guys (from this site no less!) say that Macs "aren't real Macs" without PPC.
Post-Intel Macs I can't see being as collectible. Intel's not going anywhere for a long time, even with their current issues. PC will just carry the torch for them instead of Apple, they can run pretty much anything Intel Macs can. Let's be real here too, Apple's position post-Intel is far, far different than it was pre-Intel. Apple's not the little guy anymore, the iPhone and iPad has turned the company into a giant. Steve's gone, and Tim Cook just doesn't have his panache. In fact, if Tim will be remembered, it'll be for the Apple Silicon transition or Apple Watch. Apple, and by extension Intel Macs just aren't "cool".
I'll keep my Mac Pro 5,1 around with me. Maybe it'll be collectible one day, but I doubt it.
