9. Francis Jeffers – Everton to Arsenal, £8m, 2001
At the time, Arsene Wenger came under attack for not developing emerging English talent, as he had so often bought foreign stars for small amounts before moving them on for twice, and sometimes thrice, the original cost.
However, Wenger can count this one as a failed experiment. Jeffers managed just four goals during his time with the club as injuries took their toll causing him to lose all confidence before sliding down the divisions into obscurity (and the Maltese Premier League).