Sir Alex Ferguson has left behind a legacy at Manchester United that will be hard to match by any of his successors.
Talent recognition was one of his characteristic traits. Young and unestablished players often looked up to the Scot as a father figure and counted on him to take them to stardom.
Portuguese star Cristiano Ronaldo, for example, was a relatively young and unknown player when the veteran spotted him. What he has since achieved at both club and international level is plain for all to see.
Given the monetary restrictions that were in place at Old Trafford back then, Ferguson often looked at signing comparatively cheaper players. It was under his expert stewardship that they excelled and gave Manchester United the success it deserved.
When Sir Alex Ferguson was tempted to spend big
Much of the importance was assigned to Manchester United's youth academy at the time of Sir Alex Ferguson's reign. The emergence of players such as Gary Neville, Paul Scholes and Ryan Giggs stands testament to the 79-year-old's preference towards the youth set-up.
However, there were times when Sir Alex Ferguson went looking for well-established players to sort out his problems. Though the transfer money involved wasn't as high as they are in an inflated market right now, they were still significant.
In the list below we are going to discuss Sir Alex Ferguson's five most expensive transfers:
#5 Anderson: FC Porto to Manchester United (£28m)
Anderson was regarded as one of the brightest young talents in world football when Sir Alex Ferguson decided to sign him from FC Porto back in 2007.
His statistics before signing for Manchester United looked impressive. He had won the Golden Ball at the 2005 Under-17 World Cup and played amazing football for Gremio. That started to interest top European clubs, with Real Madrid and Chelsea also keeping track of the player. But it was Manchester United who acted first.
However, with Wayne Rooney moving down to play the number 10 role at Old Trafford, Anderson was used as a central midfielder. The role was new to him and he found it hard to settle in.
Despite that, Anderson enjoyed an impressive first season, winning both the Premier League and the Champions League accolades. He scored from the spot in the big European final against Chelsea.
Unfortunately, his initial promise faded, with injuries contributing to his woes. He never really got the chance to get back to his former self. Anderson finally left Old Trafford two years after Sir Alex Ferguson's retirement.
#4 Wayne Rooney: Everton to Manchester United (£33m)
Wayne Rooney was just 18 years old when he left Everton to join Manchester United in a £33m deal. The youngster said the chance to work with Sir Alex Ferguson and some of the world's greatest players to create a special team made him sign.
He had an immediate impact, scoring 17 goals from 43 appearances during the 2004-05 season. His contributions, though, weren't enough for Manchester United to win the Premier League.
As time went on, Rooney began stamping his authority on Sir Alex Ferguson's team. He developed excellent chemistry with Cristiano Ronaldo and then with Carlos Tevez during their Champions League-winning campaign. The trio contributed towards 71.8 per cent of Manchester United's goals that season, finishing with 79 goals and 29 assists.
By then, Sir Alex Ferguson had started using Rooney in a deeper position as a number 10. The player was at ease in his new role and became one of Manchester United's best tacklers in midfield.
Rooney combined with Dimitar Berbatov and Robin van Persie later on to give his club consistent success.
#3 Dimitar Berbatov: Tottenham to Manchester United (£34m)
Dimitar Berbatov had been a target for cross-city rivals Manchester City. However, it was Sir Alex Ferguson's persistence that helped Manchester United seal the deal. He met the Bulgarian at Manchester airport itself and persuaded him to choose the red and white jersey.
Berbatov had a good idea about where the goal was and could position himself in areas of the pitch from where it would be easy to score.
Standing six feet, two inches tall, Berbatov was a physical presence inside the opposition box. In the then recently concluded season, Berbatov had been involved in 37 goals for Tottenham, scoring 23 of them. His first season at Old Trafford saw him make 25 goal contributions.
However, Berbatov developed a reputation for being languid at times. His combination with Wayne Rooney failed to bear fruit for Manchester United. In their first season together, the pair combined to create just one goal against West Brom in a 4-0 win. The main reason behind that was that both Rooney and Berbatov had similar traits and tried to drop back to instigate play.
The 2010-11 season turned out to be the most productive of his Manchester United career, as he scored 21 goals for Sir Alex Ferguson's side.
However, his chances began to wane and in 2012, following the arrival of Robin van Persie, Sir Alex Ferguson decided to let him leave.
#2 Juan Sebastian Veron: Lazio to Manchester United (£38m)
Amidst much fanfare, Juan Sebastian Veron arrived at Manchester United in 2001 for a then record £38m fee from Lazio.
Sir Alex Ferguson had just led his side to three successive Premier League titles but was looking for more at European level. With the signing of the Argentine, Sir Alex Ferguson tried to switch from his usual 4-4-2 to the 4-5-1 formation.
The former Lazio man was an instant hit, scoring four goals in his first nine Manchester United games. He ended the season with 40 appearances and eight goal contributions.
Manchester United benefited hugely from his exceptional through balls from midfield, opening up the opposition defense. However, the extreme physicality of Premier League football started to take a toll on him. He was more comfortable playing European games where the tempo was relatively slower.
Veron was often wrongly criticized by the British press, angering his manager. Over time, though, Sir Alex Ferguson came to realize that Veron's inclusion was damaging the team's midfield set-up, which had become accustomed to the combination of David Beckham, Roy Keane, Paul Scholes and Ryan Giggs.
The high-profile midfielder was eventually sold to rivals Chelsea after just two seasons, at a much lower price.
#1 Rio Ferdinand: Leeds United to Manchester United (£41m)
Sir Alex Ferguson had drawn the wrath of Leeds United fans once before when he lured Eric Cantona away from Elland Road in 1992. And it happened again in 2002, when the Scot snared up another one of their star players - Rio Ferdinand. The move cost them a record £41m. Leeds United had a desperate need to sell as they were facing serious financial difficulties and the move made sense.
Over the next 12 years, Ferdinand earned the stature of a Manchester United legend. His Old Trafford stint was not devoid of controversy, though, as he was slapped with an eight-month ban by the FA after missing a drug test.
However, those setbacks failed to have any impact on Ferdinand's Manchester United career. He was in incredible form during the 2006-07 and 2007-08 campaigns, helping Sir Alex Ferguson's side win back-to-back Premier League titles.
He combined exceptionally well with Serbian defender Nemanja Vidic to turn the Manchester United defense into a brick wall.
The 2007-08 campaign was extra special for Manchester United. It was a season where Manchester United managed to get their hands on the Champions League trophy - only the second of Sir Alex Ferguson's tenure.
Ferdinand was at the heart of the Red Devils' defense on that occasion as well. The Champions League medal gave his career a sense of fulfillment.
The latter years of Ferdinand's Manchester United career were marred by injuries. However, Sir Alex Ferguson's side got glimpses of the veteran's former self whenever he was fit.
He finally bid adieu to Manchester United in 2014, a year after the departure of Sir Alex Ferguson.