4) Leroy Sane - €51.1m
Why did Pep Guardiola see fit to spend £37m on a 20-year-old winger? Well, Leroy Sane had been lighting it up in the Bundesliga with Schalke for a couple of seasons and had established himself as a starter for Die Knappen.
At City, he was given the freedom to express himself on the flank and his explosive pace with the ball at his feet saw Premier League defenders (particularly the full-backs) struggle to keep up.
"Pep told me, ‘Play how you played at Schalke because you were free there’. The other players are all normal human beings." - Sane
His dribbling skills were what made him such a tough player to go up against but where he needs to improve is his crossing.
Sane finished the season with nine goals and five assists. Not bad for a player who is not always in the starting lineup thanks to the myriad of attacking options Guardiola has at his disposal.