Sounds to me as if nothing's changed in the last 50 years. Textbooks, especially college text books, were unbelievably high priced even back then. And I suppose the limited market resulting in very few of each book sold contributes to the cost. It was college professors who told me there was a saying among college professors to either "publish or perish"; i.e., if you wanted to keep your job and status, you had to write books. The next problem is, how do you sell them? Well, you can require your own students to use your own book in your class, but most consider that to be poor form. So, if you and I are both college professors and we've both written books, then you require your students to buy my textbook and I'll require my students to buy your book. That was the system long ago, and it sounds as if it hasn't changed. I only had one class in which the professor used his own textbook, and he was one of those characters who was convinced that he knew everything there was to know about everything. And of course, the rest of us considered him to be an idiot.