WHO co-wrote ESB with Leigh Brackett? Lucas? No, Jariten, from what I remember ESB was a collective effort of two writers. Sadly, Leigh Brackett died of cancer after finishing the rough draft of the screenplay. I was developed by Lawrence Kasdan. Sure as hell it was not Lucas.
And Civ is right that Lucas later on bouth the fights from Fox. They had no idea what they were doing, they never thought the film would be such a succes. They opted for the quick money rather then long term deal. Eventually, it was Lucas who was the winner commercially.