Kevin Costner Says Wife Christine is Using Plastic Surgery Expenses in Child Support Demand

Kevin Costner says his estranged wife is living in outer space thinking she's entitled to $248,000 a month in child support, because some of her alleged "expenses" include her own plastic surgery ... according to court docs filed by Kevin.

Kevin's forensic accountant says in the new divorce docs, the expenses Christine Baumgartner uses to justify a quarter-mil a month are outrageous. One of the expenses Christine lists includes more than $100,000 in cosmetic surgery -- her own. There's also thousands of dollars in boutique shopping, huge ATM withdrawals and other expenses Kevin's people say have nothing to do with child support.

A lot of what Christine lists as expenses are on credit card bills ... including her own attorney's fees.

And, Costner's accountant says there are one-time expenses that have nothing to do with child support, such as construction loans.

According to the docs, Kevin has been paying all the expenses for the kids, and will continue to do so. He says the reasonable amount -- the amount he is currently paying ... $51,940 a month.

As we reported, Christine has now agreed to leave the family house and get a place of her own by the end of August. His lawyer, Laura Wasser, will appear in court on July 5 to make sure Christine is ordered out by the end of August, if not before. At that hearing, we're told Christine will contest the validity of the prenup, and Wasser will argue it's rock solid.