One reason not to have such a public custody battle: To keep your personal finances private! Britney Spears and Kevin Federline's finances are now public knowledge, thanks to some revealing court documents. Britney earns approximately $737,000 monthly, saving and investing none of that income. She spends $49,267 in mortgage for two houses, $16,000 for clothes and $102,000 on entertainment, gifts and vacations, $4,758 on dining out and a paltry $500 in charitable contributions. Not surprisingly, K-Fed's lifestyle is far less lavish. Although the sometime rapper-actor earned more than a $500,000 from entertainment and endorsement deals last year, after business expenses, he only grossed $7,436. But he gets $20,000 in spousal support and $15,000 in child support monthly from Brit. He spends $7,500 in rent and $6,000 in security, $2,000 for clothes, $5,000 on entertainment, gifts and vacations, and $1,500 eating out. As for his debut song, "Popozao," Kevin earned $3,300 in royalties — now that's a shocker!