Excluding textbooks for classes, I bought this for ~$300 (several several years ago as a special treat)
Most of my collection is thrifted/bought from garage sales (for a quarter to a dollar usually) but I do have a handful of nicer ones.
$200+ on a textbook (many years ago, even) which netted me $25 when I sold it back to the college. What a racket.
I have a large box of technical books. C, C++, Java, Linux admin, UNIX, etc. My local bookstore no longer takes them. What do I do with them? Book burning party? :-/