Off topic for this thread, but still of interest I think: when buying text books not for college (i.e., when exercise order and page numbering don't matter), I'

Off topic for this thread, but still of interest I think: when buying text books not for college (i.e., when exercise order and page numbering don't matter), I've saved hundreds over the last years buying international editions through e.g. Abebooks. Like, the book mentioned in the parent is 6$ (!) with free shipping (!!!) from India: http://www.abebooks.com/servlet/SearchResults?an=sipser&sts=t http://www.abebooks.com/servlet/SearchResults?an=sipser&sts=... . These are usually either used or new international/Indian editions. The quality is not as good as the 'real' versions (very thin paper, binding not very solid) but the savings are substantial. I bought a book a few weeks ago that I couldn't find for less than 120 euros here in Europe, and it cost me ~20 euros including shipping from India.