Asia, China in particular has an insatiable appetite for...

Asia, China in particular has an insatiable appetite for anything and everything that’s related to the NBA franchise!

The late superstar Kobe Bryant amassed a large amount of his fortune from the marketing of his apparel and footwear gear in the greater Asia market place!

Your math and due diligence are great, as accurate number support the underlying concepts of sales figures.
Where I think you might be lacking an understanding of this very early Blockchain gaming (NFT) roll out is there is indeed a very very small number of investors/collectors/players supporting these ridiculous looking prices that are being paid today!
(ridiculous, maybe or maybe not)

Once the market becomes a little more main stream amongst the gaming community in the future, hopefully we will see a much higher volume of users high should translate into a more normalized looking price paid per collectible NFT, etc...

The free market place will dictate what that eventually will be, just like with tangible collectibles as we know them today!
Do you remember when only a small number of people could afford to buy the first release of the large flat screen TV sets when they were first released for sale versus what you can buy them for today?
(I realize flat screens are not collectible items, but simply what scaling up can do to price points)

Maybe not a perfect analogy, but something to consider as we see prices paid for these digital items that make your head spin today))

all above just my opinion