I had a few classes where we didn't have a textbook, but rather the professor had us buy a packet of note slides as the textbook replacement. It still cost us $15 a book, yet was essentially 50 pages of double-side copy paper put into a plastic ring binding and paper-card cover. The only reason for charging $15 a book was because that's how much kinkos charged to bind the pages together.
Publishers charge a 'decent' fee to print, bind, and ship textbooks. That's why they cost so damn much, especially when it's a specialized class with a limited print pushed through. They got equipment to pay off and executive under salary. And everyone wants a profit from each slice of the process. But $140 a book is a total scam.
I wish all my classes gave me the option of printing my books at kinkos for $15.