It's one of the biggest scams ever that would make even Ponzi blush. Issue new textbooks every year and call them revisions, which cost about as much as a quarter of tuition itself.
I don't understand why someone like Amazon doesn't jump in and have the textbooks on a Kindle, so students don't destroy their backs carrying textbooks.
Some years ago I was in graduate school and saw international students coming to class with the international edition of the textbooks we were using. Same book as ours but 1/3 the price.
I asked the bookstore manager why American students many of whom had less income than the foreign students, could not buy the books at his store. The answer: the textbook publishers did not permit those editions to be sold in the USA.
Thank God for Amazon. Now students can buy used books and international editions for much less. Also, professors can choose edition of the book just before the new edition. Students would pay $50.00 a book instead of $250.00.
Amazon does have most textbooks on kindle.
As my son finished his graduate degree; he also rented through Amazon at a fraction of the cost. Both hard copy and electronic versions of books.