> If someone has item A that's worth 10 million dollars and you have that same item A but it was only sold for 10 dollars then the first item A, despite being the same as yours, is more valuable, and therefore people and eventually apps will deal with it rather than with yours.

That's not "the market", that's sunk cost fallacy. If I buy a painting in a jumble sale for £5 and a reputable auctioneer confirms it's a genuine Picasso original, collectors will be willing to pay millions for it. If I spend £1m on a print or a painting by my sister, the auctioneer will still tell me none of their collectors are interested.

As I said, in general the most valuable versions of items will be from original authors and not from your sister.

My sister did the painting! Her paintings are original and absolutely fine, just not remotely interesting to collectors. Me paying a silly amount for it has no real effect on that. Similarly, a Picasso picked up for cheap from someone who didn't understand art is still worth millions because collectors care about the current and future desirability of Picasso originals, not whether the last buyer/seller was an idiot. And collectors obviously also pay a lot more in real terms for Picassos than anyone ever paid Picasso.

Or to look more closely at your example, the resale values of a mint condition Harry Potter first edition bought for £10 and a Harry Potter first edition bought for £30k are exactly the same and exactly the same collectors and auctioneers will deal with it, precisely because assets are identical and the market cares about how collectible the asset is rather than its individual historic price. (The market price of a first edition owned by Rowling herself is also the same, but she can change that pretty easily with a signature to make it more 'special' than other first editions)