Although the world-record set by Gareth Bale's €100 million move from Tottenham to Real Madrid last year still stands, we have seen the €80m barrier broken twice this time around. The British transfer record was also shattered, while Barcelona enjoyed a lavish final window before their ban on signings is expected to begin in January.
With clubs enjoying greater commercial and broadcast revenues than ever, and on the back of the shop window that is the World Cup, clubs have been increasingly willing to take the plunge in the market - but which are the biggest deals of the summer?
Luis Suarez may have seen his World Cup end in ignominy, but it wasn't long after his time in Brazil that Barcelona paid what was the biggest fee of the summer - a staggering €88m - to bring the Premier League player of the year to Spain.
Upheaval| James Rodriguez was part of a summer of big change at Santiago Bernabeu
Not to be outdone by their Clasico rivals, Real Madrid splashed out €80m on James Rodriguez, who captured the attention of the world with his Golden Boot-winning performances in Brazil and promptly moved to the Spanish capital from Monaco. Interestingly, this is the only transfer in the top 10 not to include a club from England's top flight.
Manchester United smashed the British transfer record to bring Angel Di Maria to Old Trafford for €75m as part of an unprecedented level of upheaval within the Red Devils' squad.
David Luiz will not be missed at Chelsea according to Jose Mourinho, but Paris Saint-Germain will hope that their €49.5m outlay on the Brazilian - the highest fee ever paid for a defender - will not go to waste. Luiz just edges ahead of Eliaquim Mangala, who became Manchester City's big-money deal of a more restricted summer by their standards. Chelsea, of course, wasted little time in reinvesting the funds, paying €44m to Atletico Madrid to bring Diego Costa to Stamford Bridge.
In seventh place is Alexis Sanchez, who became Arsenal's second-most expensive player when he joined from Barcelona. Just behind him is Luke Shaw, whom Manchester United made the costliest teenager in football history when they forked out just over €37.8m to Southampton for his services.
Shaw's new United team-mate Ander Herrera is ninth in the table, with Athletic Bilbao receiving €36.5m for the midfielder, while in 10th place - the third deal involving Chelsea in the top 10 - is Cesc Fabregas, who joined for €36m. The Spaniard edges out Romelu Lukaku, who departed Stamford Bridge for Everton for €35.4m.
A number of other significant summer moves just fall short of a place in our list. Toni Kroos and Antoine Griezmann both cost a fraction over €25m as they joined Real and Atletico, while Mario Mandzukic - Costa's replacement at Atleti - is down in 15th with a fee of around €22m.
Juan Iturbe is the most expensive signing made by a Serie A side, with Roma's new attacker placed ahead of Alvaro Morata. Jeremy Mathieu became the most expensive defender ever over the age of 30 when he joined Barca, while Ciro Immobile was the priciest Borussia Dortmund arrival of the summer at €18.5m.
Medhi Benatia makes the top 15 after his late move to Bayern Munich in August - a deal which makes the Moroccan the most expensive Bundesliga signing of the window.
Ivan Rakitic and Marcos Rojo are also within the top 25, with Mario Balotelli edging his way into the mix after his €20m move to Liverpool - a transfer matched in value by Danny Welbeck's dramatic late move to Arsenal.
|TOP 10 MOST EXPENSIVE TRANSFERS OF SUMMER 2014
|2||James Rodriguez||Monaco||Real Madrid||€80m|
|3||Angel Di Maria||Real Madrid||Manchester United||€75m|
|4||David Luiz||Chelsea||Paris Saint-Germain||€49.5m|
|5||Eliaquim Mangala||Porto||Manchester City||€44.5m|
|6||Diego Costa||Atletico Madrid||Chelsea||€44m|
|8||Luke Shaw||Southampton||Manchester United||€37.8m|
|9||Ander Herrera||Athletic Bilbao||Manchester United||€36.5m|