Harry Potter Behind the Glass CaseBooks
At the 29th annual International Antiquarian Book Fair in Boston signed copies of the six Harry Potter books are as sought-after as first-edition books signed by Ernest Hemingway, Robert Frost and noted recluse J.D. Salinger.
While more than 300 million copies of Rowling's six books have been sold worldwide, hard-to-find editions of the HP books, especially those signed by J.K. Rowling, go for thousands. A signed copy of "Harry Potter and the Prisoner of Azkaban" marred by two printing errors, is said to be worth an estimated $14,000.