Booksellers worldwide are looking forward to the magical ringing of cash registers this summer: the seventh and final installment of the Harry Potter saga will be published on July 21st, its American publisher Scholastic has announced.

Yes, I know that most cash registers don't really "ring" anymore, but that's besides the point. Retailers are expecting the same kind of sales boost to their bottom line that they've gotten from the previous books in the Harry Potter series.

Also getting a boost is the book's price: "Harry Potter and the Deathly Hallows" sports a retail price of $34.99, the first price increase in the series since 2003, according to the trade publication Publishers Weekly. But never fear, Amazon.com is already making the book available for pre-orders at $18.89. That's a hefty discount even by Amazon's standards, and it will be interesting to see if other retailers try to match that price.

PW reports that Scholastic has received the manuscript, but that no page count is yet available. (Amazon does not list even an approximate page count on its site.) Previous books in the series have weighed in at over 600 pages, and as many as 800 pages.

According to Scholastic, the previous Harry Potter book, "Harry Potter and the Half-Blood Prince," was the fastest-selling book in history, selling 6.9 million copies in the first 24 hours of its release. Amazon.com says it sold 1.5 million copies. That book, the sixth in the Harry Potter series, was published in the summer of 2005.

The first four Harry Potter books have been made into hit movies. The fifth movie, "Harry Potter and the Order of the Phoenix," is slated to debut on July 13, just eight days before the release of "Harry Potter and the Deathly Hallows."

Since Harry Potter and his author J.K. Rowling are English, it may seem ironic that the latest Harry Potter epic will not be for sale at many independent booksellers in its home country, PW notes. It says that they "won’t carry the title because of deep discounting by other retailers and e-tailers."

Bloomsbury will publish the book in the U.K., also on July 21st.