LOS ANGELES: American R&B singer Beyonce Knowles’ wig collection has been estimated to be worth half a million dollars. According to a friend, Knowles, who is married to US rapper JAY-Z, has wig for every possible occasion, reports thesun.co.uk. “The majority of them are custom-made from real hair and she’s probably got $1 million worth of stunning wigs,” the friend told In Touch magazine.To stop the collection expanding beyond control, the former Destiny’s Child singer also donates her old wigs to a charity that helps cancer sufferers.