My brother is super into buying and selling sports memorabilia on ebay (baseball cards, jerseys, etc) and this whole episode reminded me so much of that. My bother talks constantly about how the entire collectibles market is unstable because it is only worth what someone is willing to pay for it.
The people who drove the market initially were buying these things for nostalgic value because it's stuff they had as a kid. But as these people are dying, the market for it is literally just being driven by collectors like himself who are buying and selling as a kind of mini investment hoping that it will be worth more to someone later. The initial thing that gave them value in the first place (i.e. the nostalgia of getting a little card on a crackerjack box of your favorite local player) is vanishing. There are a lot of questions about whether or not the market will crash as people who don't actually care about these high value nostalgic items get "stuck" with them.
All of this seems to have a lot of parallels with the NFT market as you've described it. It's essentially a collectors market being treated as investments. Curious to see how it plays out, but I don't think I'll be jumping in just yet.