MLS has quietly become a hotbed for exciting young talents to demonstrate their skills to the world and eventually land lucrative moves to some of football's biggest clubs.
Scouts across America are now scouring the continent for the next wonderkid and are taking plenty of gambles in the South American market or by promoting their own youth academy stars into the first team.
Subsequently, we've seen a number of top footballers leave MLS in recent years, where they have gone on to become recognised stars of the game on the global stage.
But who are the top 15 most expensive outgoing MLS stars in the division's history? Buckle up and we'll run you through this prestigious list.
15. Tim Howard to Manchester United - $4m
Howard may not have enjoyed the best spell of his career with Manchester United, but he went on to experience some great highs with Everton and the United States national team.
14. Hector Villalba to Libertad - $4m
Villalba joined Atlanta in 2016 and he dazzled in an impressive first season there, scoring 13 goals in 34 appearances. He never quite reached those peaks again and was sold on to Club Libertad in 2020 for a fee of around $4m.
13. Clint Dempsey to Fulham - $4m
Arguably the greatest American footballer to have graced the Premier League, Dempsey arrived at Fulham in 2007 and set about becoming a proper baller. He carried the Cottagers to a Europa League final before landing himself a move to Tottenham in 2012.
He finally hung up his boots in 2018.
12. Maurice Edu to Rangers - $4.4m
Edu moved to Rangers in 2008 and spent four seasons in Scotland before joining Stoke City. He only made one appearance for the Potters in a three-year spell and finally returned to MLS in 2015.
11. Jack Harrison to Manchester City - $4.4m
Manchester City signed Harrison from their partner club New York City FC back in 2015 and then immediately loaned him out to Middlesbrough for some English football experience.
The youngster endured a tough spell on Teeside but he then found his home at Leeds, where he would help the Whites gain promotion in his second season at the club. He's now killing it in the Premier League during his third year in Yorkshire.
10. Carlos Gruezo to Augsburg - $4.5m
Gruezo did enjoy a two-year stint at Barcelona (not that Barcelona) before eventually winding up at FC Dallas in 2016. Three years later, Augsburg decided they liked what they saw and snapped up the Ecuadorean midfielder for $4.5m.
9. Matt Miazga to Chelsea - $5m
One of the many players to sign with and then make a mere handful of professional appearances for Chelsea, Miazga arrived with high expectations and a $5m price tag.
He's still technically a Blue, although he's slogging away in his fourth loan spell away from Stamford Bridge, this time at Anderlecht.
8. Giancarlo Gonzalez to Palermo - $5m
Costa Rican defender Gonzalez played only 17 times for Columbus Crew in 2014, but it was enough to convince Italian side Palermo to splash $5m on his services.
He suffered relegation with the Rosanero in 2017.
7. Brenden Aaronson to RB Salzburg - $6m
This is an exciting one. Aaronson broke into the USMNT at the tender age of 20 and the right winger's heroics then caught the eye of talent spotters Red Bull Salzburg.
If there's any club in Europe that knows a wonderkid when they see one, it's the Austrians. Watch this space.
6. Mark McKenzie to Genk - $6m
McKenzie is another American youngster who has made a splash on the European scene. He has collected two USMNT caps and, like Aaronson, has bagged an exciting move to Europe, this time to Genk.
The future is bright for the United States.
5. Zack Steffen to Manchester City- $7.5m
Can you get much bigger than a move to Premier League giants Manchester City? The Citizens paid a handsome $7.5m to sign Steffen from Columbus Crew and he is now learning his trade at one of the most impressive clubs in Europe.
He's even been rewarded with some game time, too.
4. Jozy Altidore to Villarreal - $10m
Altidore became the most expensive MLS export in history in 2008 when he signed for Spanish side Villarreal for a whopping $10m. He only featured nine times in three seasons with the Liga giants, before moving to the Netherlands where he tore it up with AZ Alkmaar.
3. Alphonso Davies to Bayern Munich - $11m
A genuine superstar of the game. Davies joined German champions Bayern as a generally unknown entity with a hefty $11m transfer fee, but over the past two and a half years, he has transformed into arguably the best left-back in world football.
Two Bundesliga titles and a Champions League trophy later, it looks like good business all round from Die Roten.
2. Gonzalo Martinez to Al-Nassr - $18m
Atlanta United splurged a decent sum of their own money to sign talented midfielder Martinez from River Plate in 2019, and although he was fairly inconsistent, he did show his ability on occasion, including scoring the winner in the US Open Cup final.
But Atlanta saw their chance to cash in on the hit-and-miss talisman, selling him to Al-Nassr for a whopping $18m a year later.
1. Miguel Almiron to Newcastle United - $27m
Here we have the number one, the most expensive MLS export in history - Miguel 'Miggy' Almiron. The Paraguayan attacking midfielder was simply brilliant at Atlanta United and earned himself a mammoth $27m move to Premier League outfit Newcastle.
While he has shown his devastating ability in flashes, he is severely hamstrung by the quality in his teammates and has cut a frustrated figure in a team seemingly on a slide towards relegation.