#2 Marc-Andre ter Stegen - €80 million
Barcelona are a club that have always been renowned for their attacking prowess throughout their history. Which is understandable given that they have had - Johan Cruyff, Ronaldo, Rivaldo, Ronaldinho, Villa, Neymar in their ranks, aside from Lionel Messi and Luis Suarez currently, who have continued to terrorize LaLiga defenders.
But, no team can win games without a solid defense, as a leaky one would undo all the exploits of in their attacking third. And that's where Barca's only German player makes himself indispensable to the squad.
Marc-Andre ter Stegen, who is now counted among the best shot-stoppers in the business, joined the Spanish side for an absolute bargain of €12 million in 2014 and has since delivered performances worth at least ten times over his transfer fee.
The Borussia Mönchengladbach youth product has got the ability to save, control the ball with the feet and keep cool even when the team is defensive all in his arsenal, which makes him a something of a wall behind a defense line led by Gerrard Pique.
Though the 26-year-old has never won the Ricardo Zamora Trophy, he could take pride in the fact that he came consistently second best only to the world's most valuable goalkeeper, who we'll be checking out next.