This From TLC..

Sotheby's Auction of HP Books

As previously reported, Sotheby's in New York auctioned four Harry Potter books personally inscribed by the author. Prices ranged from $9660 for a copy of Harry Potter and the Philosopher's Stone to $48,000 for Goblet of Fire; also auctioned were copies of Chamber of Secrets and Prisoner of Azkaban.

Other Harry Potter books are due to auction in London tomorrow. Neither JKR nor her father have commented publicly on the reasons for the sale.