A rare first edition copy of a Harry Potter book has sold at auction for £68,812 (around $90,000) which Design Taxi notes far exceeds its estimated valuation of £40,000 to £60,000. Harry Potter and the Philosopher’s Stone was first released in 1998, in an initial run of around 500 copies, and would later go on to sell over 120 million copies worldwide.

The first edition of the book is a fascinating historical record when compared to the scale of the global franchise it would go on to spawn. It contains a couple of typos including one on its rear cover where “Philosopher’s” is misspelled as “Philospher’s,” and another where a list of equipment includes a repeated line. It’s an inauspicious start to what would go on to become one of the best-selling books of all time.

The copy was signed in 2003

Although it’s not exclusive to the first edition of the book, this copy also features a bizarre illustration on its back cover of a wizard who never appears in any of the Harry Potter books. It later turned out the illustrator decided to invent a character based on his father rather than depict one of the wizards described in the book. The image was eventually replaced with a picture of Albus Dumbledore.

Unfortunately, if you’ve also got a first edition copy of the book, then it’s unlikely to be as valuable as this copy, which was signed by J.K. Rowling herself back in 2003 in advance of it being sold at a charity auction.

Correction: A previous version of this article falsely claimed that the book’s illustrator, Thomas Taylor, didn’t read the book prior to drawing its cover. This is incorrect. We have updated the article to reflect this.