A SIMPLE £1 coin found by a shopkeeper has fetched a whopping £1,250 at auction.
Diane Bath, 62, discovered the rare coin on September 16 when loading change into the till at the post office where she works.
The batch of King Charles 2023 £1 coins had been delivered straight from the Royal Mint.
But Diane and her colleague quickly realised that it looked "unusual".
It turned out the coin had an ultra-rare, never-seen-before error - it had accidentally been produced in the wrong metal.
The yellow-coloured £1 was brass, rather than the usual two-tone nickel.
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After consulting an expert, Diane was told it could fetch a huge £600 at auction - 600 times its usual value.
But, when she took the coin to an auction at Ryedale Auctioneers in Yorkshire on October 18, Diane was met with yet another shock.
It ended up selling for more than twice its estimated worth - at £1,250.
The ecstatic Diane said: "The first bid came in at £400 then it just kept shooting up to £500 then £570.
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"Finally, it was a lady on the phone who placed the winning bid for £1,250.
"Everybody clapped and it was such an exciting day.
"We're thrilled to bits that it's gone to someone who really wants it."
It comes as a bag of rare 50p coins was sold for an enormous £17,000 at auction, following a bidding war.
And a £2 coin with a Captain James Cook design sold for £57 on eBay.
How to spot rare coins and banknotes
Rare coins and notes hiding down the back of your sofa could sell for hundreds of pounds.
If you are lucky enough to find a rare £10 note you might be able to sell it for multiple times its face value.
You can spot rare notes by keeping an eye out for the serial numbers.
These numbers can be found on the side with the Monarch's face, just under the value £10 in the corner of the note.
Also if you have a serial number on your note that is quite quirky you could cash in thousands.
For example, one seller bagged £3,600 after spotting a specific serial number relating to the year Jane Austen was born on one of their notes.
You can check if your notes are worth anything on eBay, just tick "completed and sold items" and filter by the highest value.
It will give you an idea of what people are willing to pay for some notes.
But do bear in mind that yours is only worth what someone else is willing to pay for it.
This is also the case for coins, you can determine how rare your coin is by looking a the latest scarcity index.
The next step is to take a look at what has been recently sold on eBay.
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Experts from Change Checker recommend looking at "sold listings" to be sure that the coin has sold for the specified amount rather than just been listed.
What are the most rare and valuable coins?
- Five rarest coins - do you have one?
- The 13 most valuable £2 coins in circulation
- How valuable are the rarest £1 coins?
- Most rare and valuable 50p coins in circulation
- Rare and most valuable 20p coins that could be worth up to £750
- Rarest 10p coins in circulation
- Rare 2p coins revealed
- How to check if you have a rare and valuable banknote