Die size has nothing to do with pricing of a product which is using this die. The die itself is not the product and you're not buying the die. The price of such product is set by the market way more than by the cost of die production.
It's not the first time you went quite far into arguing for this statement.
But the arguments might be over semantics.
When someone says that die size impacts the price they don't mean that is the most important aspect (althought it might even be at times, but that's not under discussion). It's just one of the aspects that plays a role.
Saying that the product's price is set by the market is like saying nothing. That's always the case for (almost) anything, so this just terminates any discussion. It's a correct view point, but it's just a view point, which doesn't allow us to inspect any details
We can just as well say that any product is always priced by the company that makes it. Also true, but given a price, why is it priced like that?
So, no one is saying we can basically compute prices for products based on die size.
Do further note that often times when multiple variables affect an outcome, when we refer to one of the variables' value it is implied that "all other things being equal". Comparisons across processes, generations and vendors might violate this "all other things being equal" but if you feel this is the case, that's a different problem and the comparisons are misleading because die size doesn't matter.
Die size obviously is a factor, since it will plainly correlate positively with price. That's it
If you take any gpu on a competitive process and shrink it in half or double its size, these new variants will have a different price