You are assuming that the actual cost of a textbook on math which hasn't changed in centuries is hundreds of dollars per student per class when in actuality wit

You are assuming that the actual cost of a textbook on math which hasn't changed in centuries is hundreds of dollars per student per class when in actuality without the profit incentive a 100M could use the same ebook over a decade wherein the unit cost is almost too low to measured even if pay excellent folks to produce a new work.