You're forgetting that unless he plans on stealing the ebooks he still has to pay very nearly the same price for the textbook just now they can make it expire (

You're forgetting that unless he plans on stealing the ebooks he still has to pay very nearly the same price for the textbook just now they can make it expire (and don't forget to tack on the price of the kindle). tl;dr [price of kindle] + [price of textbook] > [price of textbook]