Goalkeepers are often underappreciated in their roles but that takes nothing away from the importance of their roles in the success of any football team.As custodians of the goal, goalkeepers are the last line of defense. More often than not, they are usually the difference between having a good team and having a great team.Reflexes, dominance in the box, good handling and more recently, excellent technique with the ball at their feet are some of the most important traits that differentiate goalkeepers.Shot-stoppers who possess most or all of these traits are ranked higher than their peers and they in turn help their teams achieve glory.Players who play in more advanced positions and are regular goalscorers or creators are usually more revered in football. This in turn increases their value and renumeration.Goalkeepers, by contrast, do not get to enjoy as much adulation or renumeration as strikers or midfielders.Jan Oblak has been named La Liga Player Of The Season 🏆🧤 pic.twitter.com/j67n4PnXU4— ESPN FC (@ESPNFC) June 11, 2021However, some goalkeepers have proved themselves over the years and this is reflected in their current market value.Here is a rundown of the5 most valuable goalkeepers in the world at the momentSource: Transfermarkt.com#5 Marc-Andre ter Stegen (Barcelona) - €60mMarc-Andre ter Stegen has proved his mettle for BarcelonaMarc-Andre ter Stegen is one of the most elite goalkeepers on the continent and he has proven himself between the sticks at Barcelona.The 29-year-old came through at Borussia Monchengladbach and made his first team debut in 2010. He made 127 appearances in all competitions for the Bundesliga side before completing a switch to Barcelona in 2014.His first season at Camp Nou saw him help the club to a second continental treble as the club's designated continental goalkeeper. The first few seasons of his Blaugrana career saw him rotate goalkeepering duties with Claudio Bravo, with the Chilean preferred in league action while ter Stegen kept goal on the continent.Bravo's departure to Manchester City in 2016 saw ter Stegen installed as Barcelona's bonafide first choice goalkeeper and he has since made over 270 appearances in all competitions for the club. View this post on Instagram A post shared by Marc ter Stegen (@mterstegen1)The Germany international is blessed with sharp reflexes and excellent command in his area, while his technique on the ball helps him act as Barcelona's first line of attack.Manuel Neuer's otherworldly talent means that ter Stegen has not enjoyed as much productivity on the international stage, with just 25 appearances made for Germany.That does not, however, take anything away from his ability which is reflected in him being one of the most valuable goalkeepers in the world.#4 Alisson (Liverpool) - €60mAlisson was the former most expensive goalkeeper in historyAs alluded to earlier, a great goalkeeper could be the difference between being also-rans and genuine title contenders and nowhere is this more evident than at Liverpool.For several years, the club were on an upwards trajectory under Jurgen Klopp but could not make that transition into being bonafide title contenders.Virgil van Dijk's arrival helped shore up the defense but the 2018 UEFA Champions League final showed the importance of having a top-tier goalkeeper between the sticks.Lorius Karius made two high-profile errors in that game and the rest is history, with Real Madrid going on to win a 13th continental crown without necessarily being better than Liverpool. View this post on Instagram A post shared by Alisson Becker (@alissonbecker)Jurgen Klopp sanctioned Alisson's purchase a few weeks later and the Brazilian has played a major role in Liverpool's success since then.He proved his mettle at AS Roma were he was known as the 'Messi of goalkeepers' and this led Liverpool to sign him for a then-record fee for a goalkeeper.Alisson's first season at Anfield saw him guide the club to a sixth European crown and he made several crucial saves along the way. He also kept 21 clean sheets in the league to win the Golden Glove, although the Reds agonizingly fell at the last hurdle in their quest for a maiden Premier League title.That long-elusive league title came a year later and Alisson recovered from an early-season injury to end Liverpool's three decades of heartbreak.Success has also been enjoyed on the international scene with Brazil, and Alisson has been rewarded for his displays with a host of individual accolades.The 2020-21 season was one of the worst of his career so far, as unfamiliar errors crept into the 28-year-old's game. However, he rediscovered his best form and scored an invaluable injury-time winner against Aston Villa, which was voted as the club's goal of the season.Alisson's brilliance has been recognized by him agreeing a new deal to keep him at Anfield until 2027.Also See: Fabrizio Romano's Transfer Roundup: Chelsea pushing for major signing, updates on Lukaku and Kane's futures and more