A hugely sought after first edition of Harry Potter and the Philosopher's Stone will go on auction for £30,000 this week.
The edition of JK Rowling's very first book is one of just 500 ever printed, making it one of the rarest copies in the world.
Around 300 prints were sent to schools and children's libraries when published in 1997 – meaning just 200 are in the hands of the public.
The first edition copy is being sold by a private owner who has been in possession of the book since it was bought in 1997.
It will be sold through Chiswick Auctions on Thursday.
According to online book marketplace AbeBooks, which specialises in rare books, hardcover first editions of the first Harry Potter book are characterised by a print line that reads 10 9 8 7 6 5 4 3 2 1 and the crediting of "Joanne Rowling" instead of JK.
The auction house is also selling a collection of children's books including a signed copy of the fourth book, Harry Potter and the Goblet of Fire, and a signed copy of Newt Scamander: Fantastic Beasts and Where To Find Them , both of which are set to fetch around £700.
The library of US novelist Paul Gallico also makes up part of the auction.
The writer, best known for The Snow Goose and The Poseidon Adventure, is acknowledged to have inspired JK Rowling's fictional creatures, Boggarts, and helped make James Bond an international success through his friendship with Ian Fleming.
Gallico's 1968 book Manxmouse contained creatures called Clutterbumphs that turn into what the viewer fears the most, just like Boggarts.
Clive Moss, head of rare books at Chiswick Auctions, said: "The collection is a tangible reminder of a writer whose presence and works continue to [entertain and inspire] us so many years after his death.
"This is a fabulous opportunity to be part of the continuing story that was and is, Paul Gallico - a supreme writer and talent with an enduring quality that never fails to entice and capture our attention."
What to look for
Harry Potter books are still in print which means for your old books to be worth more than face value, they have to offer something a little bit different.
First editions – especially of the first two books – are worth at least £20 no matter what state they're in and can be worth thousands and thousands of pounds.
“Bonhams sold a set of first editions of the Harry Potter books in 2005 for £14,400, and on two occasions in 2007 sold copies of The Philosopher’s Stone for £9,000,” Matthew Haley, head of books at auction house Bonhams, previously told Mirror Money .
“That first book in the series is worth hugely more than the subsequent volumes, and condition is everything. More recently first editions of the first book in fair condition have sold for around £4,000. Obviously genuine signatures or even better inscriptions by JK Rowling can add tremendously to the value.”
Other things to looks for are rarer versions of the books – ones with different covers, illustrations, large print – basically anything out of the ordinary that's no longer available.
Where can I sell my books?
Online book specialist AbeBooks is a good place to go to find out what copies like yours are being sold for – as they have signed and rare version of almost everything available - although eBay.co.uk and Amazon Marketplace also have older editions for sale.
To save you time though – here's what to watch for and what's worth what:
Harry Potter and the Philosopher's Stone (1997)
Only 500 hardcover copies were printed of the first edition, which means they can sell for tens of thousands of pounds.
Look for a print line that reads "10 9 8 7 6 5 4 3 2 1" and the crediting of "Joanne Rowling" not JK.
Standard first editions sell for anything between thousands and £20 depending on their condition and the print run.
You can also get as much as £1,800 for first editions of the 1999 deluxe edition and early versions of the Australian and US print runs (where it's called Harry Potter and the Sorcerer's Stone – printed in 1998)
Harry Potter and the Chamber of Secrets (1998)
Another valuable one to have in your collection – published in 1998 in not many numbers (Harry Potter mania and massive print runs only came into being with Goblet of Fire in 2000).
Hardcover first editions make four-figures and other early print versions make hundreds – with early versions of the deluxe editions making thousands.
Harry Potter and the Prisoner of Azkaban (1999)
A mistake in early versions of this 1999 book mean if you find one with Joanne Rowling (not JK) printed on the copyright page it will be worth over £1,000.
A good condition hard cover first edition sells for a few hundred pounds, while any version of the deluxe edition makes from £15 for more than £3,000 depending on the edition and the condition.
Harry Potter and the Goblet of Fire (2000)
There are a few versions of the fourth book out there – with different covers on the American and UK first editions.
These can sell for several hundreds of pounds depending on the condition.
A standard copy of the first edition can be picked up for about £10 though – so don't count any chickens.
Quidditch Through The Ages/Fantastic Beasts and Where to Find Them (2001)
First released as charity books for Comic Relief – this pair of books has since been re-printed many times (and one is even being turned into a film).
If you have a boxed, hardback versions from 2001 it could be worth more than £300, while good condition soft backs are sold for more than £50 as a pair and around £25 each.
Harry Potter and the Order of the Phoenix (2003)
By the time the fifth book in the series came out, JK Rowling was a global phenomenon.
That means there are a lot of first editions out there and they are worth less than earlier versions.
That said, anything signed by JK Rowling is worth four figures and versions signed by the illustrator are worth well over £100. Good quality first editions can fetch £50 though.
Harry Potter and the Half-Blood Prince (2005)
Sadly you can pick up a first edition of Harry Potter and the Half-Blood Prince for as little as £6 – meaning to make some serious money yours will have to stand out.
An illustrated deluxe edition could be worth hundreds, while a good condition one with the adult covers can fetch more than £100.
A standard edition needs to be basically pristine to make more than £50.
Harry Potter and the Deathly Hallows (2007)
The sheer numbers of first editions on the market, mean even signed copies of the final Harry Potter book can be found for less than £100 – although in good condition they'll still fetch more than £1,000.
Excellent condition books with less usual covers (ie adult, deluxe and some overseas printings) can still be worth more than £100 though.
The Tales of Beedle the Bard (2008)
This is a surprise winner in the collectible Harry Potter books stakes.
Not only is it the most expensive Harry Potter book ever (thanks to a hand-written copy going for £1.95million at auction), anyone who snapped up one of the collector's editions was on to a winner.
These cost £50 at the time, but are now selling for anything between £200 and £1,000.
Standard editions of the hardback versions can also make more than £50 in good condition.
