50 currently pays Shaniqua Tompkins $10,000 a month for care of Marquise, plus another $15,000 a month for household expenses, the New York Daily News reported Saturday.
Tompkins wants more cash, so the rapper took her to settle the issue in front of a judge.
"She is insatiable," said the rapper's lawyer, Brett Kimmel. "Her demands keep escalating."
But, Tompkins' lawyer, Raoul Felder, said $300,000 a year isn't enough to keep Marquise in "the appropriate manner."
"This guy is worth tens and tens of millions of dollars," Felder said.
Forbes magazine reported that "Fitty," who will be back in court Thursday to continue the hearing, earned $33 million in the last year.