Information on Harry Potter collectibles and their market values is contained in Harry Potter Collector's Handbook (Krause Publications 2010) by William Silvester of Victoria.
Softcover
Page Count: 272
Size: 6 x 9
ISBN: 9781440208973
Other Features: 400 color photos

According to publicity information: "In this book readers will find hundreds of listings, images and secondary market values for Harry Potter collectibles. There is an index to make it easy to find whatever one is looking for, from rare first editions worth thousands of dollars to commonplace toys, ornaments, stamps, coins, t-shirts, jewelry and costumes. In many cases there is a fine line between primary and secondary market items as something bought in a store one day can be sold in an on-line auction the next. On any given day, typing 'Harry Potter' into the search box on e-Bay will bring up over ten thousand items for sale. The values listed in this book are based on an average of prices realized in various online auctions, prices charged in online stores and the retail values of new products over the past year."

This book is unofficial and unauthorized. It is not authorized, approved, licensed or endorsed by J. K. Rowling, her publishers, or Warner Bros. Entertainment Inc.