#3 Manchester United (€747 million)

Manchester United's transfer market participation has increased considerably since they broke the British transfer record for Angel Di Maria in 2014. Since then, they have made a couple of expensive signings and it seems that spending cash has gained an equal importance alongside youth development in the squad's building.
They have just edged Spanish giants FC Barcelona, despite the latter's heavy spending activity in January.
The money spent, however, hasn't delivered the expected results. Of course United have won trophies, but the Premier League and the Champions League titles have eluded them for quite a time now.
United broke the world transfer record when they signed Paul Pogba (€105m) in 2016. He is still their most expensive acquisition, albeit no longer the most expensive footballer. He is followed by new signing Romelu Lukaku (€84.70m) and French wide man Anthony Martial(€60m).