From well-publicised transfer strategy about-turns in Russia to Real Madrid's need to ship out a few first-team players to make way for Gareth Bale, a huge amount of money has changed hands.
In fact, the £630m spent by Premier League clubs this summer is a new record - and many on this list have benefited tremendously from the liberal spending in England.
There's only one English top flight club in the top 10 earners - no prizes for guessing that one though.
And there's just one club from outside Europe - again it's not too hard to guess who if you think back over the top 10 most expensive players sold this summer. A certain Brazilian perhaps?
Anyway, let's get right to it - all the transfer fee valuations have been taken from transfermarkt.co.uk - enjoy!
Click through the slideshow to begin the top 10 countdown...