Football fans love debating transfers and arguing over whether a player is really worth the money that's been paid. 

Many suggest that in recent years that the market has become overinflated, with football clubs paying well over the odds for players who have barely proven themselves. 

This summer alone, Sean Longstaff has been linked with a £50 million move to Manchester United, while Leicester's Harry Maguire is said to have an £80 million price tag.

It's not out of the question to suggest that clubs will pay that money and if they do, many will brand those two as 'overpriced'. 

But they won't be the first players in history to be given that title - plenty have over the years and some have even gone on to make their critics look silly. 

With more potential big-money moves this summer, let's take a look at 10 players who went on to completely justify their 'overpriced' label. 

Virgil van Dijk - Southampton to Liverpool, 2018 (£75 million) 

There's only one place to start really. A lot was said when Van Dijk became the latest in a long line of players to swap Southampton for Liverpool. 

Even Gary Neville had doubts, saying that the Dutchman wasn't worth the money. But he, like so many others, were completely wrong. 

Van Dijk hasn't just improved Liverpool's defence, he's totally transformed it. Before he arrived, the Reds were conceding an average of 1.21 goals per game in the 2017/18 season. 

In the following campaign, the club shipped an average of 0.58. Van Dijk was key to that, and helped guide Liverpool to Champions League glory. 

Didier Drogba - Marseille to Chelsea, 2004 (£24 million)

When Drogba completed his switch from France to England in 2004, even Chelsea owner Roman Abramovich had his doubts. 

He had told Jose Mourinho he had the funds to sign anyone in the world, but the Special One chose Drogba, a relative unknown at the time. 

"Mr Abramovich, pay - pay and don’t speak," were Mourinho's now-famous words to the owner - and his faith paid off big time. 

Drogba spent nine years at Stamford Bridge and lead Chelsea to four Premier League titles, four FA Cups, three League Cups and the Champions League. 

£24 million seems like a bargain now. 

Jordan Henderson - Sunderland to Liverpool, 2011 (£20 million)

It may not sound like it these days, but £20 million was a hefty sum back in 2011. Liverpool's decision to spend that on Sunderland's 21-year-old midfielder certainly raised eyebrows. 

When Henderson was put on the cover of FIFA 16, some fans reacted with anger and confusion, even suggesting they would boycott the game.

'How could he grace the game's cover next to Lionel Messi?' so many asked. 

But those who did have been left pretty red-faced. Henderson has just captained his club to Champions League glory.

He's one of the first names on Jurgen Klopp's teamsheet and an important part of Gareth Southgate's England team.

It may have been a long time coming, but Henderson is now getting the respect he deserves. 

Gianluigi Buffon - Parma to Juventus, 2001 (£32.6 million)

Before Kepa Arrizabalaga, Alisson Becker and Ederson made big-money moves to the Premier League, Juventus' Gianluigi Buffon the world's most expensive goalkeeper. 

It was a record held for 16 years, so that puts his £32.6 million fee into context. It was a groundbreaking transfer that many were struggling to comprehend at the time.

But 18 years, 21 club trophies and one World Cup winners medal later, Buffon is regarded as a legend of the game. 

He spent 17 of those years with Juve and has since returned after a short stint with Paris Saint-Germain.

At 41, he could finally be part of a Champions League winning squad in 2019/20, before likely retiring and taking up a new role in Turin.   

Rio Ferdinand - Leeds to Manchester United, 2002 (£30 million) 

Rio Ferdinand's transfer from Leeds to United made massive headlines, not only because of the rivalry between the two clubs. 

The £30 million fee made him the most expensive defender in history, at the age of just 24. 

But six Premier League titles, a Champions League winners medal and 81 England caps later, he retired as one of the greatest defenders of his generation. 

Kevin De Bruyne - Wolfsburg to Manchester City, 2015 (£55 million)

Kevin De Bruyne's spell at Chelsea was considered a huge failure. He failed to break into Mourinho's team and was soon booted off to the Bundesliga.

After impressing with Wolfsburg, Manchester City brought him back to England, but the Belgian came with a hefty price-tag. 

Sky Sports pundits Phil Thompson and Paul Merson were quick to ridicule the fee, saying that De Bruyne wasn't a '£50 million player' and that the money was 'bonkers'. 

They were only saying what most were thinking at the time - but it didn't take long for the midfielder to prove everyone wrong. 

When he's fully fit, De Bruyne is the star in Pep Guardiola's team. Back-to-back Premier League titles have already been secured and it's widely believed that City will soon conquer Europe. 

Jamie Vardy - Fleetwood Town to Leicester City, 2012 (£1.7 million)

A fee of £1.7 million seems far too low to be on this list. But in 2012, Jamie Vardy was a 25-year-old striker with no Football League experience. 

Leicester paid a seven-figure sum for a non-league footballer, but their bold choice paid off. 

Vardy helped his side win the Championship in 2014 and many believed the Foxes would go straight back down.

But after avoiding relegation in their return season, Leicester shocked the world by storming to the Premier League title 12 months later. 

En-route to their historic accomplishment, Vardy netted 24 goals, with 11 of them coming in consecutive games, meaning he broke Ruud van Nistelrooy's long-standing record. 

In any other context, £1.7 million for a Premier League record holder is a ridiculous bargain, but not many would have seen the 'Vardy Party' coming back in 2012.

Dani Alves - Sevilla to Barcelona, 2008 (£28.5 million) 

Back in 2008, Dani Alves was the hottest property in Spain. Man United and Chelsea were interested before Barcelona eventually swooped. 

The Telegraph called the transfer fee 'astonishing' - but the only thing that word should be used to describe these days is the Brazilian's career. 

Alves is the most decorated footballer in the world, winning 41 major trophies for club and country. He also re-invented the role of the right-back, playing higher up the field than most. 

Guardiola was the man who brought him to the Nou Camp all those years ago - and another of his full-back signings is next on the list. 

Kyle Walker - Tottenham to Manchester City, 2017 (£50 million) 

Spurs fans thought they were laughing all the way to the bank when they realised City had shelled out £50 million on their English defender. 

But it's quickly become evident that Guardiola views Kyle Walker as one of his most important players - similar to Alves during his time at Barcelona. 

While Spurs are yet to win a trophy, Walker has two Premier League titles in two years with City and he'll likely keep his place in a team that's only going to get stronger and stronger.

Yaya Toure - Barcelona to Manchester City, 2010 (£24 million)

Before Yaya Toure was an all-conquering Premier League powerhouse, he was described as an 'average' midfielder at Barcelona. 

Merson, whose words about De Bruyne came back to haunt him, also had some questionable things to say about Toure. 

"The Ivorian is an average player who’s rumoured to be on £200,000 a week! Does he score goals? No. Does he create them? No. Is he an OK holding midfield player? Yeah." 

The Sky Sports pundit gave the transfer a 2/5 rating, but Toure went on to post 5/5 performances almost every week.

He helped guide City to their first-ever Premier League title before two more followed, along with an FA Cup and two League Cups. In hindsight, £24 million seems like a stroke of genius.