#3 Joao Felix - €80 million
Joao Felix is one of the most exciting young attackers in the game. Nevertheless, eyebrows were raised when Atletico Madrid splurged a whopping €127 million for the then-teenager's services in the summer of 2019.
Following a breakout season at Benfica, the 21-year-old has largely failed to replicate the same exploits at Atletico. He has scored just 19 times in 76 games across all competitions.
The young attacker, who remains a work in progress, made a promising start to his 2020-21 campaign for the eventual champions but faded as the season progressed.
Felix is also yet to make his mark for Portugal, scoring just thrice in 18 appearances. The 21-year-old, who plays as a second striker, played just one game at Euro 2020 as holders Portugal crashed out of the competition in the Round of 16.
#2 Jadon Sancho - €100 million
Manchester United finally succeeded in their year-long pursuit of Jadon Sancho, as they managed to land the English winger on an €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 the team'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 lives up to the pressure of his lofty price tag and produces befitting performances.
#1 Erling Haaland - €130 million
Erling Haaland is one of the most prolific goalscorers in the game at the moment, usurping the likes of Cristiano Ronaldo and Lionel Messi. He made a sizzling start to life in the Champions League, becoming one of the youngest players to score a hat-trick on his competition debut.
The young Norwegian has gone from strength to strength since then. He has continued to score goals galore since moving to Borussia Dortmund last year and is now the subject of interest from a plethora of top clubs across the continent.
Haaland has scored an impressive 60 times in as many games for the Bundesliga giants, with 41 of these strikes coming last season.
Considering the interest in his services, Haaland is unlikely to remain at Dortmund for too long. Nevertheless, the 21-year-old has opened his 2021-22 campaign with a hat-trick in the DFB Pokal as he looks set for another goal-filled season.