Mario Gotze (Borussia Dortmund to Bayern Munich for £31.5M): By far, the best deal when compared to Ozil, Neymar, Cavani and Bale.
Gotze would have made the list if he played a couple more games at the standard he is playing at right now.
Currently he is one of the most efficient players in Europe (four league goals from 15 shots; three UEFA Champions League goals from eight shots).
But this slideshow will not project what happens in the future. As of now, he narrowly misses out.
Mesut Ozil (Real Madrid to Arsenal for £42.5M): Has to be world-class week in, week out to justify his transfer fee.
Where was he against Chelsea? Quiet against Napoli. Registered an assist against Manchester City but Bacary Sagna created more goal-scoring chances that game.
Does Ozil lead Europe's elite leagues in assists? Nope. Does he lead in goal-scoring chances created per game? Again, no.
Pound-for-pound, there is no doubt Borussia Monchengladbach got a better deal for Max Kruse, who has scored and created a combined 13 league goals than Arsenal did for Ozil (scored and created combined 11).
Neymar (Santos to Barcelona for £48.6M): £48.6 million or wait one year and get him on a free transfer when he wanted to join the club.
"But Real Madrid could have signed him!" Was he going to replace Cristiano Ronaldo?
Trust Barcelona to spend £48.6 million on another forward despite desperately needing to reinforce the back line.
Came up big in El Clasico and needs to play at that standard every match.
Edinson Cavani (Napoli to Paris Saint-Germain for £55.6M): Lorient's Vincent Aboubakar is one league goal behind Cavani and cost £55.6 million less.
Gareth Bale (Tottenham Hotspur to Real Madrid for £78M): In 45 minutes against Atletico Madrid, Gareth Bale had one shot on target and did not create a goal-scoring opportunity.
Shrunk in his first El Clasico whereas Neymar rose to the occasion.
Bale can pad up his stats against irrelevant teams but he must perform in the important games.