For nearly two decades, Britney Spears paid her ex-husband Kevin Federline a staggering $40,000 a month, but he claims in his upcoming memoir that he was barely able to scrape by. "When Britney and I divorced, the court awarded me $20,000 a month in child support. At the same time, I was receiving alimony, another $20,000 a month, for half the duration of our marriage. A marriage that lasted two years and change," Federline, 47, writes in You Thought You Knew. "People hear figures like that and think you're financially set. But the reality is far from that.