It’s amazing how many books (the physical type, no batteries, ;-)) I’ve bought since I started the masters. I try to take advantage from the used books market, always on the look out for the 1p ones in Amazon UK (around €5 with handling and shipping). For the new ones, I usually go to Book Depository, were they are a little bit cheaper than in Amazon UK.
So, I’m running out of shelf space; my wife complains about the piles that keep growing in my desk; and I’m happy with the all thing. Go figure!