Usher's Ex-Wife I Need $50,000 To Kick Your Ass in Court

2/11/2012 12:20 AM PST

Usher's Ex-Wife: I Need $50,000 to Kick Your Ass in Court

Usher's ex-wife Tameka Raymond is asking the singer to dig his own legal grave -- by handing over $50,000 to cover HER attorney's fees and other legal investments she's made ... to strip him of child custody.

Tameka filed the docs in Fulton County Superior Court in Georgia -- asking a judge to force Usher to pay her $15,000 to cover her expensive lawyer fees ... plus an additional $35,000 for other costs.

According to the docs, the other costs in their custody dispute include the retention of various expert witnesses, hiring private investigators, and procuring out-of-state depositions.

Tameka claims she's entitled to the money because of the vast disparity in income between her and her ex -- a disparity that puts her at a disadvantage while she's trying to build her case.

Tameka has been trying to get full custody of the ex-couple's two kids since December -- when she asked a judge to strip Usher of joint custody, citing a laundry list of reasons ... including canceling her Saks 5th Avenue credit card.