Sam Goldwyn, a movie producer during Hollywood's Golden Age in the 1930s and 1940s, once remarked about

Question:

Sam Goldwyn, a movie producer during Hollywood's Golden Age in the 1930s and 1940s, once remarked about one of his stars: "We're overpaying him, but he's worth it."
a. In what sense did Goldwyn mean that he was overpaying this star?
b. If he was overpaying the star, why would the star have still been worth it?