A rare Harry Potter first edition is expected to sell for €50,000 or more when it goes under the hammer next week.
The book, Harry Potter And The Philosopher's Stone, was bought by an English ex-pat to help his children learn English growing up in Luxembourg.
It had been sat on a bookshelf for 21 years when the owner decided to check and see if it was a rare copy.
Some 500 first edition copies of the book were printed, 300 of which were sent to schools and libraries. This book is one of the remaining 200, and the fourth to be found by Hansons Auctioneers' book expert Jim Spencer in a year.
Although original estimates set the price at £20,000 to £30,000, the good condition could mean it fetches as much as £50,000 (€55,000) when it goes up for sale on October 13.
The retired vendor, who worked in aviation and asked to remain anonymous, said: "A couple of months ago when JKR (Harry Potter author JK Rowling) bounced into the main news I decided to reread the Potter series. I knew there had been a few first editions sold recently and Hansons was featured on the BBC website so, just to be safe, I checked the criteria.
"I did not think mine would be valuable as it was certainly not purchased when first published. I was very surprised and shocked to see that it did in fact tick all the boxes, but still could not quite believe it until I checked with Jim Spencer."
He said the book had only been read once, although his children had stuck some pictures in the back after the first film came out.
There are various ways to identify a Philosopher's Stone first issue, published by Bloomsbury in 1997, including duplication of "1 wand" on page 53. Most importantly, the issue number must read "10 9 8 7 6 5 4 3 2 1".
The book, which would pave the way for Harry Potter to become a global success, arrived at the auction house wrapped in a tea towel.
The owner said: "I was a big fan of the Potter books when I first read them. There are a lot of ethical and human behaviour discussion points in the books and I had a lot of respect for JKR for producing such a polished and nuanced body of work.
"I sent it to Hansons in a tea towel as a little nod to the Hogwarts house-elves, especially Winky and Dobby."
Mr Spencer said: "True first issues are seriously scarce.
"This new copy deserves to do really well because it's in astonishingly good condition. I would love to see it make €50,000. When the vendor contacted me, he said he'd come to me because I'm 'the number one man in the world for Harry Potter' - what a wonderful compliment."
The money from the sale will be used by the vendor to pay off his daughter's student loan and help her apply for a mortgage.
Mr Spencer said: "I was very moved by the vendor's story. This book helped his daughter prepare for school, and now it's going to help her buy a home."