In the 90s in the US, for more hard science and math courses, the course was taught against course notes that you needed to buy from one of the many print shops next to the university. This was spiral bound, often a couple hundred pages and costing 20-40$ because that is how much a short run print job costed. These were made by the instructors.

For courses where a book was required, you could check a book out from the reserve and photocopy the whole thing on one of the many high speed photocopiers on campus that all shared a linked card system, so you didn't have to use coins.

I graduated from a US university in 2018 and my favorite math course was taught by a professor who told us at the start that the textbook was just his course notes, which he provided a PDF for, and we were welcome to (and encouraged) use the text as open-notes in our exams so long as we had a printed version of the notes.

The class proceeded to be one of my favorite math classes, and it was so incredible to have a text that was deeply integrated to the course--because it was just straight up what he lectured from. I wish more of my courses had been that way.

There are teachers who care, and then everyone else.

I went to San Jose state university a decade ago. It wasn't unexpected to find that some books could be bought there similarly where you pay for basically a photocopy bound with a spiral binding.

This is how I did my entire CS grad (4 years full time) in Brazil.

Never got a single book.