The Red Devils always spent well under Sir Alex Ferguson, but since his departure in 2013, there have been a series of high-profile moves that haven't worked out.
The club have smashed British and world transfer records in their time in their pursuit of returning the good times to the red half of Manchester.
But who are United's ten most expensive signings in their history?
10. Mason Mount - £55million
Mount is a new addition to United, having only joined from boyhood club Chelsea in the summer of 2023 for an initial £55million.
There are add-ons that could take the deal up to £65million, but as of now, it's a £55m deal.
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The England international has yet to score for the Red Devils, with injuries limiting his impact.
But Mount is a very capable player, and given time, he should prove to be a good addition.
9. Bruno Fernandes - £55.7million
When you see some of the other players on this list, you will realise that Fernandes was something of bargain, although the fee could still increase over time.
The Portuguese international joined United from Sporting Lisbon in January 2020, and he's been an excellent addition, providing an incredible number of goal contributions.
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In just over 200 appearances, the captain has directly contributed to 128 goals.
While a brilliant player, some have questioned his attitude.
Despite this, United fans would dread to think where they would be without Fernandes.
8. Angel Di Maria - £59.7million
Di Maria looked to be an unbelievable signing for Man United, but it all turned sour very quickly.
The Argentine moved to Old Trafford from Real Madrid in the summer of 2014 after four years with the Spanish giants.
Things started relatively well for the winger, scoring three and setting up six goals in his first 11 Premier League games, but he never scored another league goal and departed the following summer.
Away from the pitch, his house was broken into, and his wife hated life in Manchester.
And on the pitch, Louis van Gaal began to use different players before Di Maria joined Paris Saint-Germain, where he spent seven years.
7. Casemiro - £60million
Casemiro is another relatively recent addition to United and joined the club in 2022 from Real for £60million, potentially going up to £70m.
The Brazilian is a born winner and enjoyed a brilliant debut season, as he helped Ten Hag's side finish third and win the Carabao Cup, scoring in the final against Newcastle.
He's reportedly on massive wages, but they looked to be worth it, with Casemiro adding some real steel to the midfield.
But since then, injuries and suspension have limited his impact, and given he's not getting any younger, Casemiro could prove to be a very expensive short-term recruit.
Certainly, he started brilliantly, but his decline is clear for all to see.
6. Rasmus Hojlund - £64million
Hojlund is United's second-most expensive striker in their history.
The young Dane joined from Atalanta for an initial £64million, but it could rise to £72m.
He's clearly raw and lacking elements of finesse in his game, but he has incredible speed and strength that should turn him into a top striker.
He's yet to get off the mark in the Premier League but has been scoring regularly in the Champions League.
Hojlund is one of the few positives in United's 2023/24 season.
5. Jadon Sancho - £73million
United finally ended a year-long pursuit for Sancho's signature in the summer of 2021.
The Red Devils tried and failed to bring him in 2020, but eventually, Borussia Dortmund caved, and he joined for £73m.
Unfortunately, it's a move that hasn't worked out, with Sancho showing flashes of brilliance but struggling to perform consistently.
And his Old Trafford career looks to be over after a public fallout with Ten Hag, and it would probably be best for both parties if he does move on because he's still young and has huge amounts of talent.
4. Romelu Lukaku - £75million
At the time of his arrival, Lukaku was one of the Premier League's best young strikers and looked as if he would score plenty for United.
In the end, it didn't quite work out like that, although he certainly wasn't a flop.
Lukaku spent two years at Old Trafford under Jose Mourinho and Ole Gunnar Solskjaer's guidance and scored 42 goals in 96 appearances.
But by the time he left, the Belgian's game time was reducing under Solskjaer, so he decided to move on.
Inter Milan came in, and the striker was a hit at the San Siro before returning to Chelsea and struggling.
3. Harry Maguire - £80million
Maguire is still the world's most expensive centre-back after his £80million move from Leicester in 2019.
The England international has since captained United and enjoyed a career revival.
Despite this, it would be fair to say he hasn't lived up to his price tag and has limitations that teams have exploited over the years.
But he deserves credit for becoming a key player for Ten Hag this year after being on the sidelines for the majority of the 2022/23 campaign.
Maguire will likely always split opinion, but he gives everything for the badge, which is more than can be said for some others.
2. Antony - £82million
Antony was one of Ten Hag's best players at Ajax and someone who he believed could be an essential player for United.
It was why the club splashed out an incredible £82million on his signature.
However, his time in England has so far been a nightmare.
The winger struggles to contribute in the final third and can often be seen throwing his arms around and displaying poor body language.
It's still early days, and he has time to turn it all around, but he must do more.
1. Paul Pogba - £89million
When Manchester United re-signed Pogba in 2016 from Juventus, it was a world-record deal.
The Frenchman had just starred for club and country and looked to be the complete midfielder who could take the Red Devils back to the top of the world.
In the end, it didn't work out like that, and by the time he left, he had two Carabao Cups and one Europa League to show for his efforts.
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Pogba proved to be a frustrating player for United fans - there were a few games in which he won them on his own, and others he would drift through.
Overall, he made 233 appearances, scoring 39 goals and providing 51 assists, but there will always be a nagging sense of what could have been with Pogba at Old Trafford.