Zac Efron is reportedly demanding between $8 million and $10 million to star in 'High School Musical 4'. The 20-year-old actor - who can soon be seen reprising his role as basketball player Troy Bolton in 'High School Musical 3: Senior Year' - is said to be asking for the staggering pay rise, despite the fact producers have yet to confirm whether there will be a fourth film in the Disney franchise. A source told Life and Style Weekly magazine: "Zac is thinking in the $8 million to $10 million range but it depends on how the movie opens and how desperately they want him back." It was recently reported Zac was so worried about his perfectly-groomed hair being ruined by the humidity at the Teen Choice Awards in Los Angeles that he asked backstage staff for hair straighteners. A source said: "One of the awards staff asked Zac who the straighteners were for, and he said Vanessa Hudgens, but it was really for him! "He said the humidity was killing his hair and that it was flat."