“Yep, text book scam. ....been going on since I can remember. ..I think the profs are in on it too. ..”
It was going on when I was a student, 40 years ago, though the prices were much lower back then. One of the electives I took was “Engineering in History,” and the professor didn’t assign us a textbook. Instead, he wrote a set of notes, which told the students everything they needed to know to pass the exams, no more, no less. Then he put the notes in duotang folders, called it the “Engineering History Compendium,” and sold them for $2 each. Even in those days, it was a great deal. I think he only got away with it because he was also the associate dean.
I had an elective with that title at UCF (FTU at that time) in about 1973 or 1974. Pretty good course actually. I kept the text book for years afterward because I found it so interesting.