If you're between the ages of 15-30 you almost certainly own at least one Harry Potter book.
I'd go as far to say that almost every household in the UK probably contains one or more of J.K. Rowling's novels.
But how much are they worth, the first book wasn't even published 20 years ago yet, surely they can't fetch any money at all?
Well, that's where you're wrong.
In an upcoming book titled J.K. Rowling: A Bibliography 1997 -2013 by Philip W Errington, the author has put his time working at an auction house to good use and has put together a chart documenting just how much early print editions of the novels are worth.
You'll need the actual book to get the exact specifics, but luckily Marie Claire have been doing their research and this is what they've come to find, unsurprisingly, the older the book the more it's worth:
Harry Potter And The Philosopher's Stone
If it was published by Bloomsbury in hardback, and the cover shows Harry standing by a train, you're onto a winner. AbeBooks, a book site, thinks you can pocket a staggering $55,000 for this rare print, especially if you have a copy that is credited to 'Joanne Rowling' instead of J.K.
Harry Potter And The Chamber Of Secrets
Apparently the softback edition of this and Philosophers will still net you a tidy $9k.
Harry Potter And The Prisoner Of Azkaban
Rowling's third novel, published by Bloomsbury, has some commercial value. It goes for about as much as the American print of the first book - which was titled 'Sorcerer's Stone' - which can go for up to $700, that's not that much money but it's a lot more than the £8 your mum bought it for.
Harry Potter And The Goblet Of Fire/Order Of The Phoenix/Half-Blood Prince/Deathly Hallows
Sadly by this point, these books were in such high demand that they were printed by the gazillions (not literally but probably). So unless you have a signed copy, which you wouldn't want to sell, or a special edition you're looking at around $200. Still, that's not too bad.