'Rare' coins have taken the internet by storm this year with the new plastic fiver selling for thousands online, followed by the tenner, which brought our attention back to the guy that sold his £1 coin for £3,000.
But the reality of us stumbling upon a misshapen coin with a distinctive dye error or a proof, is pretty low - which means if you want one, you may have to think outside of the box.
This includes looking at coins that have low circulation values - or investing in the ones that look slightly odd - in the hope that one day, they'll be worth some treasure.
Or you can have a go at a competition offering you the chance to win one - if you're feeling particularly lucky.
Change Checker - a website that specialises in finding and valuing new and rare coins - is offering you the chance to win a rare 20p - which the Royal Mint has described as an "error" edition.
This means it encountered a flaw during production - in this case, it's the ‘Bronze 20p’ flanked by a 20p and 1p coin from the same year.
After examination by x-ray fluorescence spectrometry, the coin was confirmed by The Royal Mint as an extremely sought-after minting ‘error’.
Somehow a 1p ‘blank’ found its way into the presses and a 20p was accidentally struck onto it - it's also significantly thinner than the standard 20p coin.
How to win it
Change Checker says it has just one coin to give away - which means there can only be one winner.
As well as the Bronze 20p, you'll also get a Brilliant Uncirculated 1p and a Brilliant Uncirculated 20p coin from the same year.
You'll have to register for the site to enter though - which may include being added to a mailing list for alerts and news updates.
If you do want to give it a go, you'll have to enter before midnight on Thursday 7 December online at Change Checker.
The draw will take place on 11 December 2017 - so if you want to unsubscribe after the competition ends, make sure it's after the 12th - as the winner will be notified though their changechecker.org email address.
