Curious Cat Question

Well, I got this from John Nery (who got this from Jessica Zafra's post about a Biblioholics Support Group), who was asking in a meme-sort of way: What are five of the best book bargains one has ever gotten?

Thinking it over, I came up with this:

1. a complete collection of Ernest Hemingway's short stories in TPB format (Books for Less)
2. a complete collection of Franz Kafka's short stories also in TPB (ditto)
3. The very rare Essential Harlan Ellison hardbound (National Bookstore)
4. A signed hardbound edition of Tim Powers' Declare. (Books for Less)
5. An ARC of Susanna Clarke's Jonathan Strange and Mr. Norrell (Booktopia)

The last one was a best-bargain because the bookshop gave it to me for free way before the book ever came to these shores. *wry grin*

So what have you gotten that you thought was really good bargain from those second-hand bins?