How to tell if you own rare first edition of Harry Potter as copy sells for over $400,000

An extremely rare first edition of 'Harry Potter and the Philosopher's Stone' with only 500 known copies has sold for £300,000 (over $400,000) at auction.

'Philosopher's Stone' was the first of the seven core novels written by J. K. Rowling which later went on to be turned into blockbuster films starring the likes of Daniel Radcliffe, Rupert Grint, and Emma Watson.

Following the huge success of the movies, a TV series is currently in development by Warner Bros., who has cast Dominic McLaughlin as the lead character, Harry.

But without the books, there would be no films or TV shows – the first of which was published in 1997.

There are key elements on the copy of the well-loved 'Harry Potter' book that was recently sold for hundreds of thousands of dollars that indicates that it was one of the extraordinary first editions.

A first edition Philosopher's Stone book was recently sold for over $400,000 (Heritage Auctions / SWNS)

First edition pointers include the Wendy Cooling review printed on the front board and the iconic misprint of '1 wand' listed twice on page 53, according to seller Heritage Auctions.

Others include the copyright page listing the author as 'Joanne Rowling', and the rear board having misprints of 'Philospher's' and 'Wizardry and Witchcraft'. So, if you think you might have a super rare edition of the book, these are the things you want to be looking out for...

All 5,650 copies of the hardback and paperback first editions were published on the same date, and neither has 'bibliographical priority', the auctioneers said.

But the hardcover edition remains notably scarcer, as only 500 copies in this binding were produced, made for distribution to public libraries.

The Wendy Cooling review on the front is one indicator of the book's rarity (Heritage Auctions / SWNS)

Auctioneer Samantha Sisler said: "This is personally one of my favourites. [...] The books were given to libraries for children to read. Finding one in this quality is quite remarkable."

After a four-minute bidding war, it sold on October 14 for £242,617.28 (over $320,000) at Heritage Auctions headquarters in Texas, US.

Including buyer's premium, it totals £303,271.60 (roughly $420,000).

The listing mentions the book – which was published by Bloomsbury – is thought to be in great condition, with light rubbing at spine ends and corners, and spine ends just pushed.

It also mentions a few minor scratches to rear board and the is text lightly browned, though less so than usually found.

It was sold as part of the Heritage Auctions rare books signature auction.

It's said that there's only 500 copies of the ultra rare book (Heritage Auctions / SWNS)

Other sales include a first American edition and first printing of 'Harry Potter and the Sorcerer's Stone' signed by Rowling which sold for £14,215.86 (approximately $18,000), including buyer's premium.

A first American edition and first printing of 'Harry Potter and the Chamber of Secrets' signed by Rowling which also sold for £3,032.72 (roughly $4,000), including buyer's premium.

A first American edition and first printing of 'Harry Potter and the Prisoner of Azkaban' signed by Rowling also sold for £3,032.72 (over $4,000), including buyer's premium.

And a first edition of 'Harry Potter and the Goblet of Fire' signed by Rowling sold for £2,274.54 ($3,000), including buyer's premium.