It’s in the interest of all professors collectively (including those who hope to be real professors someday) to prop up the problematic idea that a book ought to cost $400+ just because it’s a textbook, because professors write textbooks, no one involved in selecting books or publishing them has any incentive to keep the costs reasonable.

> no one involved in selecting books or publishing them has any incentive to keep the costs reasonable.

There is an difference in having no incentive to keep costs down and having an incentive to keep costs up. Some professors are simply indifferent to their students' plights. As far as these professors are concerned their students are just an inconvenient bleep in their oh-so-important life. Extracting money from them is not on their radar.

The vast majority of professors don't write textbooks. In fact there are probably a lot more profs who do care, and assign open books, or no books at all, than professors who make a living writing textbooks.

> difference in having no incentive to keep costs down and having an incentive to keep costs up.

Sure, but the only interested parties here presently are:

- students

- publishers

- professors (a few of which "author" or "customize" textbooks and stand to profit)

Students have zero power, publishers have every incentive to increase prices, and most professors don't get involved because like you said, it's not really relevant to them personally.

I agree that if a significant contingent of professors and lecturers essentially started boycotting the "textbook" industry, by using and contributing to "open source" books, or at least authoring or collaborating to author content that they give to their students at no cost, that would amount to applying pressure to the exploitatative business model.

I had a professor mention that they were apathetic to piracy of their own books because they received about a nickel per copy.