4. Zinedine Zidane
Bought for: £3m by Juventus in July, 1996
Sold for: £45.8m to Real Madrid on 09.07.2001
Juventus surely have a claim in the biggest bargain in football history in retrospect, snapping up Zindeine Zidane two years before World Cup heroics with France for just £3m.
Zidane grew into a proficient, dazzling playmaker supreme in Serie A and eventually persuaded Madrid to obliterate the world transfer record in 2001, a move which paid dividends with Champions League success thanks to a Zizou wonder-goal just a year later.