Here are the richest authors of all time. According to Most Expensive Thing, Elisabeth Badinter is the world's most valuable author, with an estimated net worth of $1.3 billion. The French philosopher is known for her books on feminism, including The Conflict: How Modern Motherhood Undermines the Status of Women. Her fantasy books and the movies, theme park rides, and merchandise they’ve inspired have earned Rowling a net worth of $1 billion. Then pick up our new book, The Curious Reader: A Literary Miscellany of Novels and Novelists, on sale now!