Yeah the textbook cartel is outrageous. I started a textbook publishing company to fight this!
I was working on web copy describing how crazy the mainstream textbook prices are, and used the price C$300 for the calculus book, trying to be flippant (to exaggerate the competitor price to make my prices look better). I decided to check the price in the bookstore, and to my surprise the price was even higher than that! (sold as bundle: book + exercise manual + solutions manual). When your real prices are higher than the pricing people use as hyperbole, you know there is a problem.
It makes no sense—for a subject that has been around for 300+ years, and virtually unchanged for the past 100.
It only works because the educators are complicit. Most bachelors degree textbooks in basic sciences do not need to change from one decade to the next. My Lorrain and Corson Electromagnetic Fields and Waves from when I was studying applied physics in 1975 is just as correct now as it was then.
The 'textbook cartel' plays the same role for authors as Ticketmaster plays for artists: they're the bad guy so that artists can charge more.
This is the kind of thing that is counted as "economic growth", too.
Well someone sat down and wrote a 1000 dense pages that probably took 2-5 years of their life. That deserves to be rewarded. Of course there are problems with professors prescribing their own books for the class etc. but when I went to school you could return that $300 book for $200 to the bookstore once the semester was done.