Friends know that I love shopping for used books. A few of my friends share my obsession, notably physicist Götz Neuneck (and, yes, that is a heavy metal umlaut).
By far, my greatest used book pick up was a 1962 copy of Glasstone and Dolan, Effects of Nuclear Weapons complete with nuclear weapons effect computer (above).
I think I paid fifty cents for mine; a copy (with computer) will run you $200 bucks or more online.