In India, at least at IITs, we get assignments and course material on email or as hardcopy kept at campus photocopy centre from where students can get copies at cheap rates. We hardly bought textbooks. The once we bought were very cheap. I think the most expensive one I bought was for $8 at current rates. Don't you guys have libraries ? Whenever I needed to consult a textbook I used to go to the library and read it there.
Moreover we get "Indian" edition of those books which are written by Americans and those used to be as cheap as Indian author text books.
On flipkart (Indian version of amazon) Introduction to algorithm is for INR621 which is roughly $10
When more than a student or two has the idea of using the library's copy, it becomes a battle over who will be able to check out the limited number of copies. Sometimes this becomes serious enough that the library will freeze the availability of a book if it's been assigned that semester.
Obviously there is something to be learned about the price differences in the different versions, but there is also a non-trivial difference in quality. I've had International Versions that were missing whole 10-page sequences, pages out of order, and different problem sets whose answers had factual errors. Also the lower grade paper is an obstacle to book reuse.
By this I don't mean to be negative, I just believe the final answer involves more reasonable digital distribution; I'm sick of the myth of "getting the exact same book for cheaper" because I've been burned by it a number of times.
The campus library may well only have one copy on reserve for a course with 300 students, or they may not stock the newest edition.
The latter part gets to be a problem in the instance where the textbook publisher decides to publish a new edition every year or two just to ensure that you'll be doing the wrong homework exercises unless you're using the same new copy the professor has.
Moreover we get "Indian" edition of those books which are written by Americans and those used to be as cheap as Indian author text books.
On flipkart (Indian version of amazon) Introduction to algorithm is for INR621 which is roughly $10
http://www.flipkart.com/introduction-algorithms-3rd/p/itmczy...
On amazon same is at $60
http://www.amazon.com/gp/offer-listing/0262033844/ref=sr_1_1...