2. John Bostock
Spurs also made a sensational bid to land a 16-year-old in 2008, leaving Crystal Palace seething as their brightest academy product for at least a decade walked away to White Hart Lane for an initial fee of just £700,000, decided by an independent tribunal.
Bostock never made a Premier League start in five years at White Hart Lane though, with a total of five loan spells at the likes of Hull City, Sheffield Wednesday and Toronto FC failing to see the attacking midfielder realise his potential.
The 22-year-old is now attempting to rebuild his career with Royal Antwerp under the stewardship of ex-Dutch international Jimmy Floyd Hasselbaink in the Belgian second division, a far cry from the bright lights of the Premier League.