EXPERTS have revealed the most sought-after collectable 50p coins right now. They might be hard to get hold of, but they could make you a good amount of money if you find them. The 50p is the most collectable out of all the coins in circulation, but you would need to find certain rare designs for it to be worth anything more than its face value. ChangeChecker regularly releases a scarcity index which keeps up to date on which coins are the most sought-after by collectors. In the coin-collecting world, scarcity usually refers to how difficult a coin is to get hold of versus the demand for it among collectors. The scarcity index combines a coin's mintage figure with how many of each design is listed as "collected" by collectors on the web app - indicating how easy it is to find each coin - as well as the number of times a design has been requested as a swap. This helps the coin experts to determine the true scarcity of a coin, as opposed to just looking at how many have been manufactured, or minted. Interest can change among coin collectors so it's worth keeping up to date with the latest scarcity index. The 2023 Salmon 50p is the rarest 50p in circulation, with just 200,000 minted. The rare coin was struck to highlight the plight of the salmon, whose population is in decline. But despite its rarity, it is actually not considered among the scarcest on the index. ChangeChecker says this is because collectors are "less likely to want to part with it, so very few swaps have taken place". These are the top five most scarce coins right now, according to the latest analysis... 1. Kew Gardens - worth up to £700 Mintage - 210,000 This 50p has become one of the most talked about collectors' coins in the last 15 years, according to the Royal Mint. It was originally released in 2009 to celebrate the 250th anniversary of the opening of Kew Gardens in London. Its reverse side features the famous Chinese Pagoda at Kew, encircled by a leafy climber plant. The coin is among the most rare 50ps in circulation and we've seen it sell for as much as £707 before on eBay. 2. Triathlon - worth up to £30 Mintage - 1,163,500 This coin is part of the set of Olympics coins released to commemorate the London 2012 Olympic and Paralympic Games. It was minted in 2011 and depicts the popular sport. The highest recent sale we've found on eBay recently was £30 on June 21. 3. Wrestling - worth up to £15 Mintage - 1,129,500 The Wrestling 50p coin comes from the same set but has a slightly lower mintage. It is considered the second rarest Olympic 50p coin after the Football one. The coin was designed by Roderick Enriquez, a graphic designer from Hammersmith, London. We've seen it sell for as much as £15 online so is worth digging around for. 4. Football - worth up to £75 Mintage - 1,125,000 As we mentioned earlier, the Football 50p is the rarest of the Olympic coins. It features an explanation of the controversial offside rule on it. It has been known to sell for as much as £75 in the past. 5. Judo - worth up to £17.95 Mintage - 1,161,500 Rounding off the top five is another Olympic coin. The judo coin was designed by David Cornell after he won a national competition. The highest bid we've seen on eBay was for £17.95 in June last year. What makes a coin rare? If you're lucky enough, rare coins have been known to sell for thousands in the past. A coin is usually considered rare if it either has a very low mintage, or if it has an error. Error coins are surprisingly valuable to collectors as the small changes to the design make them particularly rare. How do I find out what my coin is worth? If you're checking your change for rare coins, you could look at websites like ChangeChecker to see which designs are usually sought after. Coin Hunter gives you an estimated valuation of your coin based on the average of the most recent sales, as well as a range of how much you can expect it to fetch. You can also check how much the coin is selling for on eBay. Search the full name of the coin, select the "sold" listing and then toggle the search to "highest value". It will give you an idea of the amount of money that the coin is going for. Remember, though, a rare coin is only worth what someone is willing to pay for it.