That's the same distinction that I make; a) Fundamental technical or scientific books, that will keep their value at least a few years, preferably longer. b)

That's the same distinction that I make; a) Fundamental technical or scientific books, that will keep their value at least a few years, preferably longer. b) Books about a certain version of a program or technology. I do buy books in the (a) category, even hardcopy. But for (b) I first look for a free online alternative, and otherwise an ebook. I've also made that mistake of buying Java 1.2 doorstops back in the time ;) The world of IT moves too fast for print. Fiction books I usually buy as ebook, because my bookshelves are already over-full and most I'll only read once anyway.