Manchester United or the Red Devils, as admiringly called by football lovers around the globe, have constantly been involved in the buying and selling of some of the star players ever.The Theater of Dreams has been a launchpad for numerous legendary players that went down in the sport's history book. At the same time, it has also been a welcoming home for prodigies who wish to grow up in the red jersey. Cristiano Ronaldo is a prime example of the same.Over the course of years, the English giants have been involved in some of the most massive transfers that football has ever seen. Speaking of which, let us discuss some of the biggest sales in the history of Manchester United.#5 Henrikh Mkhitaryan | Manchester United to Arsenal (€34m) | 2018A high-profile swap in 2018 saw Henrikh Mkhitaryan and Alexis Sanchez switch sides. A strong name within the young legions of Borussia Dortmund, Henrikh Mkhitaryan grew up under the Bundesliga outfit's favorite manager — Jurgen Klopp.Mkhitaryan rose to fame at Dortmund under KloppManchester United landed a much awaited transfer to bring Mkhitaryan to England. However, a lack of playing time and indefinite playing roles forced the Armenian to look for better turf.EXCLUSIVE: Manchester United midfielder Henrikh Mkhitaryan agrees move to Arsenal in a deal that will see Gunners forward Alexis Sanchez go opposite way. It’s a straight swap, no money involved. Paperwork complete, Mkhitaryan will undergo a medical over the next 2 days #MUFC #AFC— David Ornstein (@David_Ornstein) January 20, 2018Arsenal seemed perfect for the former Signal Iduna Park native, who moved to the Emirates Stadium without a single doubt. Although Alexis Sanchez got the best out of the swap-deal among the duo, the sale remains the fifth most in Manchester United's history.#4 David Beckham | Manchester United to Real Madrid (€37.5 m) | 2003Arguably the most marketable footballer of all time — David Beckham, ended up being one of the most famous Galacticos in Real Madrid's money-splashing era.Beckham is said to be the most marketable player in the history of footballA thorough gentleman with a handsome face and infinite talent could be an asset to any team. David Beckham's off-field fame helped Manchester United grab the Asian market in terms of profitability.After spending the majority of his career in the red jersey, the former England international accepted an unrefusable offer from the Santiago Bernabeu. In the process of breaking headlines following the switch, Beckham earned Manchester United enough to fatten their wallets.On this day in 2003: David Beckham officially joined Real Madrid 💰 pic.twitter.com/2zgW0feVFM— Goal (@goal) July 1, 2021David Beckham enjoyed a productive stint at Real Madrid just as with Manchester United. He later joined LA Galaxy.