I am sure it is legal to ask for the pay sheet, but no seller would give you that. Sellers usually do not price discriminate merchandise that is not differentials within the same country since commerce within the country cannot be easily restricted.

That is where brands come in for differentiable products. The generic brand lotion and the name brand lotion might come from the same factory. Maybe it is even the same product, or the different in quality is only slightly better for the name brand. But now the seller can target people willing to pay $x for lotion, and people willing to pay $2x for basically the same lotion.

Or you implement “binning”, where products of worse quality get branded differently, even though the sale price difference between the better quality product and the generic quality product is disproportionately larger than the cost to produce the better quality product than the generic product.

Anyway, you cannot do this for a movie or tv show, so the sellers of movies/tv shows do it more crudely via country or region of the world.