Brits are being urged to check their wallets, purses and down the back of their sofas as a 50p coin sold for more than £200 this week.
The rare coin, which was released in 2009, marks 250 years since the opening of Kew Gardens opening in 1759.
The Royal Mint produced around 210,000 of the coins, which feature the Chinese Pagoda at the Royal Botanic Gardens and a portrait of the Queen.
Selling the coin on auction site eBay, its previous owner listed it for just 99p on March 5.
However, multiple interested parties soon sparked a bidding war, with 11 buyers looking to get their hands on the rare coin.
Eventually, after 26 bids, the coin was sold for £234, 468 times its 50p value.
What makes a coin valuable?
The 50 pence piece has become the most valued and collected coin in the UK, with many collectable designs appearing on its heptagonal canvas.
Its 27.5mm diameter makes it the largest of any British coin, and allows space for decorative pictures. It has often been used to celebrate big events over the past 50 years of British history.
The rarest coins tend to be of the greatest value, with the mintage (number of coins with each design made) being the fundamental attraction for collectors.
Along with the design, other aspects of the coin which increase value are the condition of the coin and whether it has an error in its design.
The way in which it is sold can also determine the coin’s value - while some coin collectors will bid vast amounts of money on ebay or at auction, others opt for more robust valuations by selling via a coin dealer.
Rarest 50p coins in circulation the UK?
The Royal Mint has revealed the most valuable 50p coin, ahead of the 1971 decimalisation’s golden anniversary.
The rarest is the Kew’s Garden 50p, which was designed to mark the 250th anniversary of the gardens in 2009. Only 210,000 coins were ever minted with this design.
The Kew Gardens 50p sells for £156.25 on average, but one seller received over £700 for one when they sold it on eBay.
The other rarest coins stem predominantly from the 2011 Olympics, with the wrestling, football and judo coins among the most valuable. Only 1.1million of each of these coins were produced.
Flopsy bunny and Peter Rabbit designs which were produced in 2018 are also highly valuable.
These coins - 1.4 million of which were minted - depict the characters from Beatrix Potter’s novels and celebrate the life of the English writer and these sell for around £5.
In 2019, 500 million coins were produced, with three new 50p designs.
These included one of Arthur Conan Doyle’s Sherlock Holmes, Paddington Bear at St Paul's Cathedral and the Tower of London.
Top 10 most valuable 50p coins, according to Royal Mint
Here is a list of the top 10 most valuable coins, when they were made and how many were minted:
Kew Gardens (2009), 210,000
Olympic Wrestling (2011), 1,129,500
Olympic Football (2011), 1,161,500
Olympic Judo (2011), 1,161,500
Olympic Triathlon (2011), 1,163,500
Peter Rabbit (2018), 1,400,000
Flopsy Bunny (2018), 1,400,000
Olympic Tennis (2011), 1,454,000
Olympic Goalball (2011), 1,615,500
Olympic Shooting (2011), 1,656,500