#3 Arthur Melo (Juventus) - €72 million
Arthur Melo arrived at Juventus as a part of a swap deal with Barcelona that involved Bosnian international Miralem Pjanic go the other way.
A year on, it can be said that the Bianconeri had the better deal. That's because even though the Brazilian scored only once in 31 games in all competitions, Arthur Melo is widely tipped for a better sophomore campaign in the Italian top flight under Massimiliano Allegri.
It remains to be seen how the 24-year-old fares after a rather underwhelming first season for the deposed Serie A champions.
#2 Kai Havertz (Chelsea) - €80 million
Kai Havertz arrived with a lot of fanfare at Chelsea last season, but has had a rather modest first campaign on the other side of the Channel.
The 22-year-old central midfielder did score a hat-trick in the League Cup, but netted only four times in the Premier League, where Chelsea finished in the Champions League qualification places.
In the Champions League, the German international opened his account in the final as Chelsea won the competition for the first time in almost a decade.
Under compatriot Thomas Tuchel, Havertz seemed to thrive in more advanced areas of the pitch, something that could continue in 2021-22 as Chelsea aim to compete on multiple fronts.
#1 Jadon Sancho (Manchester United) - €85 million
Manchester United finally succeeded in their year-long pursuit of Jadon Sancho, as they managed to land the English winger on a €85 million transfer this summer.
Only 21, Sancho has had a successful four-season stint at Borussia Dortmund, scoring 50 goals and assisting 64 times across competitions. In fact, Sancho's tally of 41 league assists in the last three seasons is only exceeded by two other players in Europe's top five leagues.
Although he made news for all the wrong reasons - he was one of three England players who missed their spot-kicks in England's penalty-shootout defeat to Italy in the Euro 2020 final - Sancho is expected to hit the ground running at Old Trafford.
It remains to be seen if the 21-year-old is able to live up to the pressure of his lofty price tag and produce befitting performances.