Academies can provide clubs with a rich source of talent. Rather than having to go into the transfer market, they can look within to reinforce their first team.
However, for one reason or another, clubs sometimes decide to part ways with their youth products.
Bigger clubs with big sums of money can tempt teams to sell, while contract disputes and release clauses can also play a role in transfers taking place.
Press the next page as we list the top 5 biggest sales of academy players during the Premier League era.