I've been scooping up old cookbooks when I come across them...mostly under a dollar, some for a quarter, a couple for a few dollars. Sometimes, actually much of the time, reading an good cookbook satisfies me far more than a novel!
My cookbook acquisitions have mostly been from the 40's to 60's lately, some dogeared and spattered, which gives me SUCH a thrill...to think I am holding a reference tool that someone turned to time and time again. And if I can find notes in the margins saying it was a success with the family or ingredients scratched out and substituted with another, ooohhhh! Even more special.