4. Sergio Aguero to Chelsea
In January 2011, Chelsea were interested in a young forward who went by the name of Sergio Aguero and were told by Atletico Madrid that they could have the striker for £35 million. Roman Abrahamovich though that it was too much money to splash on such a young player and instead submitted a £50 million bid for the then prolific Fernando Torres.
Roberto Mancini thought that it was wise to invest so much money in the player and willingly parted with £35 million to secure his services. The results of the transfers stand in stark contrast to each other. Aguero banged in 30 goals in his first season at Manchester City as well as scoring the decisive goal against Queens Park Rangers which helped Man City win their first Premier League title in decades. Torres, on the other hand, only managed 1 goal in his first season and has gone on to become one of the biggest flops of all time.