Barcelona have high hopes for 75-million-euro signing Frenkie de Jong AFP/JOHN THYS The January transfer window is supposedly a market for desperate buyers but Barcelona sit five points clear at the top of La Liga and have made more signings than any other team in the division. On Monday, it was Kevin-Prince Boateng doing kick-ups at the Camp Nou and three days later came Frenkie de Jong, the 21-year-old Dutch midfielder for whom Barca will pay Ajax 75 million euros ($85 million), with a further 11 million euros due in add-ons. “In De Jong, we add talent, youth and a player with Barca style,” said president Josep Maria Bartomeu. “He will be a key player in the next few years.” Boateng and De Jong, who will join in July, follow Jeison Murillo from Valencia, a central defender for the present, and Jean-Clair Todibo from Toulouse, another to mould for the future, who will also arrive in the summer. REAL SPENDING LESS Barcelona go up against Catalan neighbours Girona on Sunday and a few hours later, less than 70 miles away, Real Madrid play Espanyol. Madrid’s most expensive player will be Vinicius Junior, the 18-year-old signed for 45 million euros last…