2. Diego Costa ( £35 million)
Diego da Silva Costa (born 7 October 1988)is a Spanish professional footballer. He began his career with Braga in Portugal, and was signed by Atlético Madrid in 2007. Costa was loaned him back to Braga, and then to Celta and Albacete before being sold to Valladolid in 2009. He returned to Atlético the following season and then joined Chelsea for £35 million in July 2014.