#4 Jack Grealish | £100 million, Manchester City

When Manchester City announced that they had bought Jack Grealish from Aston Villa, it was the reported fee that shook the footballing world. The Cityzens handed Aston Villa £100 million, effectively making Grealish the most expensive English player in history.
The 26-year-old might have been Aston Villa's best player for nearly a decade, but is he worth such a price tag?
So far this season, he has scored two goals and made two assists in ten games for City. That's hardly as good as Gabriel Jesus' seven direct goal contributions in nine games or even Ferran Torres' four direct goal contributions in just seven games.
Manchester City might have just spent world-class fees on an above-average player, but it's still too soon to tell. Grealish might still light up the league before the season comes to an end.
#3 Antoine Griezmann | €120 million, Barcelona

Atletico Madrid have been the real winners in Antoine Griezmann's case. They bought him for just €30 million in 2014 and he won three trophies with them in five years. His transfer to Barcelona saw Atletico receive €120 million, but after poor performances and racial controversies, Barca have loaned the star back to Atletico with an option-to-buy clause set at just €40 million.
Although he spent three seasons at Barcelona, Griezmann won only one trophy with the club. His debut season saw the star falter in front of goal, eventually scoring just 15 goals in 48 appearances, a stark difference from the 29 goals in 49 appearances he pulled off at Atletico.
His performances at the Wanda Metropolitano saw the star score just over one goal per two games on average. However, at Barcelona, he could only manage one goal in over three games on average. These are still great stats for most strikers, but hardly for one that cost €120 million.
#2 Phillipe Coutinho | €142 million, Barcelona

Barcelona seriously need to curb their spending habits, especially now that the club is struggling financially, because Philippe Coutinho is their third player on this list. Granted, the former Liverpool star seemed to effortlessly light up Anfield with his driving runs and remarkable right foot. However, his best post-Liverpool performance was for Bayern when he scored two goals against his parent club Barcelona.
Although he scored over 10 goals per season in his first two seasons at Barcelona, Coutinho couldn't adapt to life at the the Nou Camp. His returns on the pitch were great for most average players, but hardly anything for a €140 million player.
When Barca loaned him off to Bayern in the Bundesliga, the star flourished somewhat, scoring a goal every three league games on average. He also won the Champions League with Bayern Munich. Coutinho is back at Barcelona now, but with 6 appearances and zero goals in all competitions this season, it's clear that Barca just wasted the extra €100 million.
#1 Neymar | €222 million, Paris Saint-Germain

Brazilian star Neymar is highly regarded as one of the very best players in the world, and rightly so. His performances at Santos included a season where he scored 42 goals in 60 games. His short four-year stint at Barcelona also saw him score 39 goals in just 51 games.
Clearly aware of his world-class status, PSG's decision to activate his release clause made sense. However, things have been bleak for the star since his exit from Camp Nou.
Neymar has no issues scoring goals, he is still the same prolific goalscorer he was at his two former clubs. However, fitness troubles and consistent injuries have seen the star sidelined far too often. He scored 28 goals in 30 games during his debut season, but the star never had lower than a 41-game season before that. The next two seasons would have him play only 17 and 15 league games respectively. If Neymar is to live up to his transfer fee, he needs to sort out his consistent injury woes so he actually gets time on the pitch.