A first-edition Harry Potter novel that was bought for 13p almost 30 years ago has sold at auction for £11,000.

The uncorrected proof copy of Harry Potter and the Philosopher’s Stone was bought in 1997 from a second-hand shop with two other books for 40p.

Harry Potter books expert Jim Spencer said: “This book so deserved to do well. This is where the Harry Potter phenomenon began.

“This is the very first appearance in print of the first Potter novel.”

The seller, who remains anonymous, bought the volume when she was 26 and lived in Crystal Palace.

It was sold by Hansons auctioneers to a UK buyer.

She said: “I didn’t have much money but I always liked to treat myself to a browse round second-hand bookshops on Saturday mornings.

“I dropped into one of my usual haunts, one of the second-hand bookshops just off the main road in Crystal Palace, looking for some Agatha Christies. Piles of books were all jumbled up in baskets on the floor with a maximum price of 40p.

“The Harry Potter book was among the piles – maybe even by accident – as all the rest were Agatha Christie, Dorothy Sayers, Ngaio Marsh etc, as far as I remember. I bought it as a throw-in with a couple of other titles – 40p for all three. I don’t think I even looked at it properly to tell the truth.”

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A children’s book featured in the last instalment of the Harry Potter series, Harry Potter and the Deathly Hallows. Individually handwritten and illustrated by J.K Rowling, the book is one of only seven copies.

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It was a rare, immaculate condition first edition of Harry Potter and the Philosopher’s Stone. This was the highest sum ever paid for a work of fiction published in the 20th Century.

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The copy had been annotated by JK Rowling and included original drawings and notes about Quidditch.

Mr Spencer said the title page mistakenly stated the author’s name as “JA Rowling” rather than “JK Rowling”, and then on the other side as “Joanne Rowling”.

The seller said she was scrolling the internet one night and found a news story about the prices some Harry Potter books were selling for.

She contacted Mr Spencer to see whether her book was valuable, and admitted that “finding it when I did was just a massive piece of well-timed luck for which I will always be grateful and more than a tad surprised”.

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