It seems like an ongoing debate if an academy can actually develop the next world class player and if that one (player) out of ??? (players) is actually worth the work or money from an economical side (having in mind that in some leagues the clubs must have an academy).
I don’t want to dive too deep into that discussion, but here are some numbers that can frame a picture for having an academy setting.
Below are the numbers of the top 50 of clubs worldwide since July 2015 regarding the transfer of players graduated from their youth academy (…and having been at the club for at least three years between the seasons of their 15th and 21st birthday).
An overview over countries is seen in the figure below.
Having a closer look onto the club level coaches will notice some familiar names.
The Portuguese club SL Benfica leads the table with about 379 mio € and a prominent face of Joao Felix.
Real Madrid (Morata) as second most profitable academy considered 330 mio € and AS Monaco (Kylian Mbappe) completed the podium with 285 mio €.
Below are the number of the top 50 clubs that collected transfers fees for players trained in the club (in € Million, since July 2015, including eventual add-ons)
Well obviously I did not consider any costs that are involved with having an academy setting, however, I would assume that even a fraction of 60 mio € (FC Nantes last position) should suffice to sustain having an academy.