I studied Hitchcock a little bit at University and knew the famous story about the Birds - that he'd tortured Tippi for a day using real birds. I had no idea that it was a five-day onslaught and that it was the tip of an iceberg that carried on through to another film.
I think how pay gets determined is pretty broad - experience how people look what they bring to the job. But there's no question women are paid less. Women don't ask.