Soccer has changed greatly over time.
During much of the 20th century, teams were expected to raise their own players from their academies or make reasonable transfer deals for players.
Before the 1990's, the most expensive player was Ruud Gullit, who made a £6 million (€7.6 million) move from PSV Eindhoven to AC Milan.
In 2012, the world's most expensive player is Cristiano Ronaldo, who cost £80 million (€102 million).
You can look at teams like Barcelona and Manchester United, clubs that aren't really known for wasting money, but even they spend great sums on wages and on certain purchases.
While it is easy to criticize the biggest spenders for wasting money, these teams have also made some very smart transfers.
In my opinion, the world's biggest spenders of the past ten years have been Real Madrid, Chelsea, Manchester City, and Paris Saint-Germain. All these sides have dished out ridiculous amounts of money on players and have wasted millions of dollars.
However, they have still been on the good end of some bargains. Here's a list of the world's four biggest spenders and their one best transfer deal.
Note: I only picked players who were bought by the club after their expensive takeover.
Out of all the teams on this list, Real Madrid have been wealthy for the longest. The Spanish side have been one of the best, if not the best, clubs in Europe since the early 1900's and have always had superb players on their team sheet.
Since the early 2000's, Madrid have spent hundreds of millions on high-profile players. Under Florentino Perez and his "Galacticos" policy, Los Merengues have been hugely successful, with five La Liga titles, one Copa del Rey and two Champions League trophies in the last 12 years.
But while Madrid have used astonishing amounts of money on players, they have also brought in cheaper players who have played superbly for the club.
One example is Mesut Ozil, who moved from Werder Bremen in 2010 for approximately €15 million.
The German international had a great World Cup in South Africa and was subsequently bought by Real. Since his move, Ozil has played in over 100 matches and has been one of the top assisters in Europe.
Madrid have already gotten their money's worth out of Ozil, and the 23-year-old is still young. Purchasing the midfielder will probably go down as one of the best transfers of the 21st century.
Chelsea have made many good purchases since Roman Abramovich's takeover in 2003, but most of them have still been fairly expensive transfers.
Players like Michael Essien, Ramires, Ricardo Carvalho and Florent Malouda have all been superb purchases for the Blues but have nonetheless been costly.
I feel that Didier Drogba just about wins as Chelsea's best bargain.
At £24 million, Drogba was expensive, but he has thoroughly justified that sum over his eight years at the club. In 341 total appearances, the Ivorian scored an astonishing 157 goals and assisted 71.
Didier Drogba has plenty of individual awards, but he will be even more proud of his club's honors. While he was at Chelsea, the Londoners won three EPL titles, two League Cups, four FA Cups and one UEFA Champions League.
Every Chelsea fan was saddened by Drogba's departure, everyone will always remember the Ivorian's last kick for the team, the kick that won the Champions League final.
Unlike the other teams on this list, PSG have yet to win any silverware since their big takeover. And that isn't too surprising because the French side became rich only one year ago.
Paris haven't refrained from splashing their money. In the summer before the 2011-12 season, the team spent €43 million on Javier Pastore and used up another $50 million (approximate) on other players, such as Kevin Gameiro and Jeremy Menez.
But it has been PSG's purchases in summer 2012 that have caught the world's attention.
In the past two months, Carlo Ancelotti has bought Zlatan Ibrahimovich for €23 million, Thiago Silva for €42 million, Ezequiel Lavezzi for €30 million and Lucas Moura for €45 million.
Les Parisiens haven't held back at all this summer, and it'll be interesting to see how well the team can do in the Ligue 1 and the Champions League.
With all these huge transfers and without much time for these players to prove themselves (as the takeover was just a year ago), finding a transfer bargain was difficult.
I chose Jeremy Menez since he only cost €9 million, is still fairly young at 25 and had a good debut season with seven goals and 12 assists in the league.
The winger has 16 caps for the French National Team and is looking to have an even better 2012-13 season.
Following Manchester City's Community Shield win on Sunday, Roberto Mancini's side have three trophies since the club was bought by Sheikh Mansour in 2008.
It took time for the Citizens to take off following their takeover but it was worth the wait as the team won the 2011-12 English Premier League for the first time since 1968.
Since 2008, City have spent approximately £930 million. When looking at their purchases, it's hard to overlook the very poor deals that were made.
Examples include Jo for £18 million, Robinho for £32.5 million, Roque Santa Cruz for £18 million, Jerome Boateng for £10 million and Emmanuel Adebayor for £25 million.
Nonetheless, Manchester City did win the English Premier League so there were smart buys along the way.
The one that stands out the most is Yaya Toure. Like for Didier Drogba, Toure was expensive but has been outstanding.
Yaya Toure and David Silva cost the same amount for City, but I feel that the Ivorian narrowly beats the Spaniard for the best bargain.
The 29-year-old is a superb box-to-box midfielder and is known for his versatility, strength and speed. Toure very rarely has a bad game and will once again be a key player for Manchester City this season