My normal policy here at Wild About Harry is not to report on eBay auctions until after they've ended. However, I know this seller personally, so I can vouch for this item's authenticity and the honesty of the seller, and this is something damn cool! (Trust me, if I had to money to buy this myself, it would not be on eBay today).
What we have here is the photoplay edition of Houdini's 1919 serial, The Master Mystery by Arthur B. Reeve and John W. Grey. While the book itself shows up on eBay from time to time, a copy in the original dust jacket is fantastically rare! The seller has this listed at a starting price of $450, which is more than fair as that is close to what the book sells for without the jacket.
You can view the auction and bid here.
The same seller/friend also has a copy of Houdini's Magic by Walter Gibson in the original dust jacket here. This is also a VERY hard book to find with a cover. Starting price on that is a very low $200.