10 Most overpriced transfers of 2018

With the transfer window now firmly shut across the Premier League, LaLiga, Ligue 1, Serie A, and the Bundesliga, fans can now sit back and take stock of their club's summer business.

The summer witnessed some high-profile moves including Kylian Mbappe becoming the world's most expensive teenager and Kepa Arrizabalaga shockingly becoming the world's most expensive goalkeeper just weeks after Alisson Becker had claimed that particular title.

Among the sometimes unbelievable sums of money spent across Europe this summer was some excellent value. We have previously covered the 10 best value transfers in 2018.

However, on the other hand, there were some transfers which made you blink, rub your eyes, and double check to ensure you weren't dreaming. It is those transfers which we cover in this feature.

We have correlated data from transfermarkt.com with actual fees paid for players throughout the transfer window to reveal the 10 most overpriced transfers of 2018 below.

Note: Market value is based on a range of factors gathered by data analysis platform, transfermarkt.com, and is correct at the time of writing. For the purposes of this list, we have excluded all players who moved on loan or a free transfer.

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#10 Willem Geubbels

Willem Geubbels is unveiled as an AS Monaco player

Market Value: €6 million

Transfer Fee: €20 million

Difference: €14 million

At just 17 years old, Willem Geubbels has already commanded a transfer fee of €20 million when moving from Lyon to Monaco in Ligue 1 this summer.

France under-18 international has caught the eye with his performances in the Lyon B team last season. The forward earned a call-up to the Lyon first team for two games last season - one in Ligue 1 and one in the Europa League.

On both occasions, he became the first player born in the 21st Century to appear in the competitions. His potential caught the attention of Monaco who quickly moved for him while paying a huge €14 million more than his market value.

While Monaco has a reputation for developing talent, such a large transfer fee for a young and generally untested player is a big risk. Time will tell if it was value for money or cash down the drain.

#9 Richarlison

Richarlison has started extremely well for Everton but cost the Toffees a huge fee

Market Value: €25 million

Transfer Fee: €39.2 million

Difference: €14.2 million

Richarlison followed Marco Silva to Goodison Park this summer for a fee of €39.2 million with an additional €10 million in add-ons possible depending on his performances.

This is an extraordinary fee for a player who is yet to earn an international cap with Brazil and has played just one full season in the Premier League. His slump during the second half of last season also raises questions about paying €14.2 million over market value for the 21-year-old.

However, the forward has enjoyed a good start to the season with Everton, scoring three goals in as many games. He has also received a red card in an eventful start to his Toffees career.

Time will tell if the money paid by Everton is good value or not, but for now, Richarlison is one of the most overpriced transfers of the summer.

#8 Kylian Mbappe & James Maddison

Kylian Mbappe (L) & James Maddison (R)

Kylian Mbappe

Market Value: €120 million

Transfer Fee: €135 million

Difference: €15 million

The world's most expensive teenager and the second most expensive transfer of all-time, Kylian Mbappe made his move to Paris Saint-Germain permanent over the summer for a fee of €135 million.

When discussing value for money there are many factors at play and as Mbappe is a very young player with a World Cup winner's medal to his name already, this transfer is perhaps not such bad business for the Parisian club.

However, according to the cold, hard facts, the French champions paid €15 million over market value for the teenager and this fee has landed the club in hot water with UEFA Financial Fair Play.

James Maddison

Market Value: €10 million

Transfer Fee: €25 million

Difference: €15 million

At the opposite end of the transfer scale, James Maddison's move from Norwich to Leicester was just as overpriced as Kylian Mbappe's move to Paris.

The attacking midfielder had impressed in the Championship last term and Leicester made him one of their main summer transfers by forking out €25 million for his services. The fee is a huge €15 million more than the 21-year-old's current market value.

Maddison has started the season brightly, playing in all four of Leicester's Premier League matches so far and notching himself a goal. The Englishman will need to continue that form if he wants to justify his high transfer fee.

#7 Abdou Diallo

Abdou Diallo is unveiled as a Borussia Dortmund player

Market Value: €12 million

Transfer Fee: €28 million

Difference: €16 million

It is rare for Borussia Dortmund to splash out extravagant fees for players so there must be something about Abdou Diallo which led to the German club paying €28 million for his services this summer.

Having spent a season at Mainz 05, the 22-year-old impressed throughout his 27 appearances for the club and made the move to Dortmund to continue his development. The France Under-21 captain is certainly a towering presence in defence and has a lot of potential but paying €16 million more than market value for any player is a huge risk and adds pressure to his performances.

So far, the Frenchman has played three times for Dortmund and it will take some more time to see if he can make the step up from having some potential to fulfil the expectations placed on his shoulders.

#6 Cristiano Ronaldo

Cristiano's transfer to Juventus was one of the most talked about from the summer

Market Value: €100 million

Transfer Fee: €117 million

Difference: €17 million

One of the more shocking and certainly among the most talked-about transfer this summer was Cristiano Ronaldo's €117 million switch from Real Madrid to Juventus.

The fact that the 33-year-old can still command such a high fee tells you everything about his marketability and playing level. However, his transfer market fee stands at €100 million, meaning Juventus paid €17 million more than what he is currently worth.

Of course, the Italian champions will make that money back from shirt sales and sponsorships which are not included on market value. However, with the Portuguese superstar yet to get off the mark for his new club, some small questions are popping up about his ability to perform week in, week out in Serie A.

#5 Riyad Mahrez

Riyad Mahrez could be the world's most expensive backup player

Market Value: €50 million

Transfer Fee: €67.8 million

Difference: €17.8 million

Manchester City's record transfer occurred over the summer when they splashed out €67.8 million for Leicester forward, Riyad Mahrez. The pertinent question about this transfer is - why?

The Citizens already boast an embarrassing array of riches in Mahrez's position and would have been better off focusing on a new defensive player either in midfield or their backline. To pay €17.8 million over market value for a player who will not automatically be in the first XI feels like a demonstration of financial power by the Manchester club and little else.

Yes, Mahrez will play occasionally this season, but it is highly likely his main role will be off the bench. The Algerian currently has a market value of €50 million, but it would be of little surprise to see that value drop if he doesn't get much game time this season.

#4 Thilo Kehrer

Thilo Kehrer in action for Paris Saint-Germain

Market Value: €18 million

Transfer Fee: €37 million

Difference: €19 million

It is little surprise to see yet another Paris Saint-Germain transfer appear on this list as the Parisian club are clear targets for extortion when purchasing players.

Thilo Kehrer made the move from Schalke 04, where he came through the youth ranks, to Paris this summer for an extraordinary fee of €37 million. The 21-year-old impressed over the past two seasons in the Bundesliga, notching up 44 appearances and four goals for Schalke 04.

However, his market value of €18 million is almost half of what the French champions paid for his services and immediately places huge pressure on the shoulders of the young German. To date, he has 2 appearances (one start, one substitute), and not been included in the squad for one of Paris Saint-Germain's fixtures.

#3 Jefferson Lerma

Jefferson Lerma has played just one Premier League game for AFC Bournemouth so far this season

Market Value: €2 million

Transfer Fee: €28 million

Difference: €26 million

This transfer tells us the two main stories of the summer transfer window. First, Premier League clubs always pay a premium even if they are not a top six team. Secondly, Columbian players enjoyed a higher transfer rate due to the World Cup.

Jefferson Lerma had spent the last couple of seasons at Levante in LaLiga playing at a decent level. However, his market value of just €2 million demonstrates that he is a very standard defender with nothing particularly special about his style of play.

Bournemouth, however, decided to splash out a club record €28 million for his services in what was one of the more shocking transfer fees of the summer. The 23-year-old made his Premier League debut for the Cherries against Chelsea and also has an EFL Cup appearance.

#2 Fred

Fred was the second most overpriced player in 2018

Market Value: €32 million

Transfer Fee: €59 million

Difference: €27 million

Manchester United could have had several players featuring on this list had Ed Woodward sanctioned Jose Mourinho's request for new defenders. However, Brazilian midfielder Fred is the only United transfer which makes the 10 most overpriced of 2018.

The 25-year-old had impressed during his five-year stint in Ukraine with Shakhtar Donetsk, leading to the Red Devils forking out a huge €59 million for his services during the summer. However, with options including Ander Herrera, Andreas Pereira, and Marouane Fellaini providing competition for Paul Pogba and Nemanja Matic, perhaps it is a signing which wasn't necessarily required.

Regardless, the Brazilian has played in three of Manchester United's opening four matches. While his performances have been good, he will need to do a lot more to justify a fee worth €27 million more than his market value.

#1 Kepa Arrizabalaga

Kepa Arrizabalaga is easily the most overpriced transfer of 2018

Market Value: €20 million

Transfer Fee: €80 million

Difference: €60 million

In what was the most shocking transfer of the summer window, Chelsea activated Kepa Arrizabalanga's release clause at Athletic Bilbao for an extraordinary €80 million, making him the most expensive goalkeeper in the world.

Fans who do not follow LaLiga had probably never heard of Kepa, but Thibaut Courtois' move to Real Madrid forced Sarri's hand and he went straight for the 23-year-old Spaniard. The transfer fee ensured that the world record paid for a goalkeeper was broken twice in the same summer after Liverpool had bought Alisson becker a few weeks earlier.

Kepa has started all four of Chelsea's Premier League games this season, conceding three times. However, having moved to Stamford Bridge for a frankly ridiculous €60 million more than his market value, it will take many seasons of top-level performances to justify such a fee.