If you're a Harry Potter fan like me, you treat your books like a precious stack of gold. Sure, I've read my cherished tomes so many times now that some pages are falling out, but I still treat them as delicately as I possibly can.
Well, it turns out you might actually be able to make some cash out of your old Harry Potter copies, as online book market AbeBooks has created a guide that lists off which books are considered precious to collectors.
If you have any or all of these, you could trade them in for some serious scratch!
1. Harry Potter And The Philosopher's Stone
If you see a print line with numbers: 10 9 8 7 6 5 4 3 2 1 and with 'Joanne Rowling' being credited, then you have one of only 500 copies of the hardcover first edition.
AbeBooks states that you can make a pretty penny that varies from $40,000 (£29,000) to $56,000 (£40,000), while a handful of advance proof copies are available from $7,500 (£5,400) to $13,500 (£9,700).
For those of you with paperback editions, you can collect a four-figure price, even a five-figure if your paperback is in top-notch condition.
2. Harry Potter And The Chamber Of Secrets
If your copy has J.K. Rowling's signature, then the first edition printings can earn you $9,000 (£6,500).
In 1998, J.K. Rowling was still a jobbing author rather than a worldwide superstar richer than the Queen, so there are a reasonable number of signed first editions available from her book tour signings.
A signed copy will easily put four figures in your pocket.
3. Harry Potter And The Prisoner Of Azkaban
Joanne instead of J.K. Rowling is credited on this edition, and the number line is 10 9 8 7 6 5 4 3 2 1, including a block of misaligned text on page seven.
People who have the 'Joanne' name can sell theirs for up to $12,000 (£8,650).
4. Harry Potter And The Goblet Of Fire
The fourth book brought about less tours for J.K. Rowling, meaning fewer books were adorned with her signature. This makes a Goblet Of Fire with a signature worth more than $10,000 (£7,200).
Look out for the limited editions with original watercolour illustrations by Giles Greenfield (Bloomsbury’s UK edition) and Mary GrandPre (Scholastic’s super rare US edition of only 25 copies).
If either illustrator has signed a copy, then prices are again in four-figures.
If you have entrance wristbands or even golden tickets from events organized for a J.K. Rowling signature, then you can be sure to add an extra zero when selling your collector's book.
5. Harry Potter And The Order Of The Phoenix
Again, J.K. Rowling's signature is the real moneymaker.
If you attended her midnight launch event in Edinburgh back in 2003, the first signed copies can rake you in four full figures.
If you have illustrator Jason Cockcroft's signature on it, your signed book can earn you $200 (£144).
6. Harry Potter And The Half-Blood Prince
If you've got a signed copy, then you can potentially make up to $5,000 (£3,600). If your copy was signed by illustrator Mary GrandPré, then you can make around $250 (£180).
As an absolute Harry Potter fan, I don't think I'd be able to give away my precious books. I personally don't have any collector's items, but I wouldn't want to sell mine anyway. I imagine that I'd one day pass them on to my kids, and they could do with them as they please.
Plus by that time, they'll probably be worth so much more.