Mauro Icardi | Sampdoria
Market Value January 1st 2012 - £175k
Market Value June 2013 - £8.8m
Difference - £8.6m
Percentage - 4900 per cent increase
The former-Barca youth team player will cap a superb 12 months by moving to Inter Milan this summer. He's gone from Nou Camp reject to Serie 'A' starlet faster than you can say La Masia.