Kevin Costner's Estranged Wife Wants $248k/Mo. In Child Support

Kevin Costner's estranged wife wants him to fork over nearly a quarter of million dollars a month to care for their kids ... but Kevin makes it clear from his legal docs, he thinks his estranged wife's ask is highway robbery.

Christine Baumgartner filed new legal docs in which she asks a judge to force KC to shell out $248,000/month in child support for their three kids. She claims that an eye-popping amount is the only way Christine and the children can "live at a standard somewhat approaching the standard that the children will be enjoying while in Kevin's care." BTW, she says that doesn't include private school tuition, health care and sports-related expenses, which she also wants him to pay.

Sources with direct knowledge tell TMZ, Kevin is already paying 100% of the kids' expenses. In addition to the expenses, Costner has filed legal docs saying he's willing to kick in an additional $38k per month.

Christine says Kevin's enormous wealth is more than enough to cover her ask ... claiming Kevin's total income last year was $19.5 million. Their family expenses, she claims, were $6.6 million. Kevin clearly thinks the money has nothing to do with child support.

BTW, it sounds like they live large ... CC lists regular trips to places like Hawaii, Aspen and the Caribbean -- where she says they often hire caterers and chefs to entertain their guests.

The upkeep of their many properties ain't cheap either ... about $2 mil/year ... says Christine.

As we've reported ... this divorce is getting uglier by the week. Recently, Kevin filed court docs of his own in which he claimed Christine refused to move out of one of his properties ... despite clear terms in their prenup that he insists required her to move out by a certain date after she filed for divorce.