When you're talking about a student who gets (government grants) or who has financial aid, they typically have money for books,
With CDs and the extra material, really what's happening is that the cost of that is being built into the textbook, and then it's being bundled as a value add, ... If we try to buy only the textbook, we're paying as much as we would for the bundled material.
It is the middle-class that don't have disposable income,
It used to be that a book changed editions every five years.