A RARE 50p coin has just sold for over 240 times its face value – and you might have one without even knowing. A 2019 Kew Gardens 50p went under the hammer on eBay for a whopping £122.09 - 244 times its face value. The coin, which attracted 13 bids, is one of the most sought-after pieces among coin collectors. The Royal Mint, the official maker of British coins, regularly puts limited edition pieces into general circulation. In some cases, extremely rare 50p pieces have sold for a whopping £950. According to The Royal Mint, the Kew Gardens 50p has become one of the most talked about collectors’ coins in the last 15 years. It was originally released in 2009 to celebrate the 250th anniversary of the opening of Kew Gardens in London. Just 210,000 of these coins were put into circulation, making them incredibly rare. The reverse side, created by Christopher Le Brun, features the famous Chinese Pagoda at Kew encircled by one exact detail - a leafy climber plant. On the other side, it shows a portrait of Queen Elizabeth II. Over the years, demand for the coin has skyrocketed, with some selling for as much as £707. For a time, it was considered the rarest 50p coin in the UK due to its low circulation. However, a new contender has taken its place – a 50p featuring an Atlantic Salmon and bearing King Charles III’s portrait. Collectors are always on the lookout for the Kew Gardens 50p, and prices continue to climb. If you think you might have one, it’s worth checking its condition before selling. Coins in pristine, uncirculated condition tend to fetch the highest prices. You can look for similar listings on eBay to get an idea of how much yours could be worth. What makes a coin rare? One of the most popular types of coins to collect are 50p pieces. This is because of their large surface area, as there is enough spaces to add new and intricate designs on. With a 27.5mm diameter, it's the biggest British coin and is used to celebrate big occasions, anniversaries, and historical events. Over the Olympics a range of themed 50p coins were printed, with the Aquatics 50p reaching up to an eye-watering £2,000 in auction. This coin soared in price due to an initial design error, which was quickly corrected, leading to very few misprints in circulation. Errors make a coin unique which means they will most likely be worth more, as there a fewer of them. Even without a misprint, if a coin has a low mintage there are fewer of them in circulation and so are deemed rare. As a general rule of thumb, the rarer the coin the more valuable they are to collectors. How to sell a rare coin If you have managed to get your hands on a rare coin, there are a few ways you can go about selling it. Online platforms like eBay, Facebook marketplace, or trading apps can be easy to use - but there are risks. Scammers may try and target sellers with this trick - they'll say they are keen to purchase the item and ask for money upfront for a courier. They have no plan on collecting the item and are only using the courier to grab free cash. When buying or selling on Facebook Marketplace it's advisable to meet up in person - make sure this is a safe space and avoid payment links. Many sellers will choose to handle cash when meeting to limit the risk of scams. To ensure the ultimate safety you can sell rare coins at an auction. This can be done through The Royal Mint's Collectors Service which has a team of experts who can help you authenticate and value your coin. Finally, you can sell rare coins on eBay.