You've touched on an important issue: some books (or texts, in general) are much related to the current state of art, and won't be very useful in 10 years. Cont

You've touched on an important issue: some books (or texts, in general) are much related to the current state of art, and won't be very useful in 10 years. Contrast SICP -- pretty much transcendental, every other hacker recognizes those four letters -- with jQuery reference. jQueries of this world come and go. Now the question is, what is the value added of having a hardcopy of SICP, and what is of having a hardcopy -- or e-copy -- of jQuery? Another issue is bit rot of e-books. With no common long-lived e-book format (perhaps beyond HTML and PDF), you can't readily expect an e-book to be handy with technology in 10 years. It's a fast changing market, as of now. So, in the end, what is a realistic price for a short-lived e-book?