Some of the early editions of Harry Potter and the Philosopers Stone have a misprint on page 53 where the item "1 wand" is repeated twice in the list of supplies a young wizard needs to take to Hogwarts to begin the first year. The missprint can seriously up the value of the book but only if it's a first edition.
“As the first book in the series, Harry Potter and the Philosopher’s Stone has a special place in the affections of the millions of readers across the world and the proof reading error about the wand in the first edition has, of course, become a treasured piece of Harry Potter arcana,” Matthew Haley, the Head of Books and Manuscripts at Bonhams. Via: The Independent. “Like most enduring books aimed at younger readers, the Harry Potter books also have wide appeal to adults and there is a strong market among collectors for first editions.