#4 Curtis Davies (Aston Villa) – £10.0mEmbed from Getty Images
Curtis Davies joined Midlands rivals Aston Villa for a hefty fee of £10m in 2008 and the switch was just one of many big-money buys during Martin O’Neill’s era as Villa manager.
The towering centre-half was regarded as the next big England prospect at the time and was on the shortlist of several clubs, but after his move to Aston Villa, Davies’ performances began to get worse and before long he was shipped out on loan to Leicester for six months.
When he returned, Davies was sold to Birmingham for a meagre £3.5m — £6.5m less than what Villa had paid for him.
Since then, Davies has played for Hull City and Derby, who he remains with today.
#3 Nacer Chadli (Monaco) – £10.0mEmbed from Getty Images
Nacer Chadli left the Albion for Monaco in 2018 following their relegation from the Premier League, with the French side paying a respectable £10m for the winger.
Chadli turned out to be far more trouble than he was worth at the Hawthorns, and spent more time sidelined with dubious injuries than playing football for the club; yet by the time the World Cup rolled around, Chadli was up and raring to go — very convenient!