You May Already Own Books Worth $200 to $5,000
There might be a book on your bookshelf that’s worth hundreds or even thousands of dollars. Valuable books can turn up at yard sales and book sales, too, where you can buy them for next to nothing.
Even though the most valuable books of the 20th century predate the 1960s, there are a fair number of books published since 1960 that have significant value. Many of these valuable modern books are from early in the careers of authors who only later became widely read.
via Hidden Treasures on Your Bookshelf | Travel & Recreation.