Today I purchased the following J.K. Rowling books from the library book store for a dollar each:
Harry Potter and the Prisoner of Azkaban (hc)
Harry Potter and the Order of the Phoenix (hc)
Harry Potter and the Half-Blood Prince (hc)
I haven't read any of the books yet, but I'm not sure I'll be able to resist going ahead and reading these out of order (these are books 3, 5, and 6 of the series.) Unlike the Left Behind books which seem to all pop up periodically in the discount section, there's no telling when or if the rest of the Potter books will show up.