Rough estimate is about $800 a month. Each state is different, but a child actually costs about $300 a week to raise. That's not counting daycare expenses, by the way. The courts usually have a mathematical formula that takes into account who has custody, and how much each parent earns. But the bottom line is that between the two, they owe about $1200 a month, combined. Now, the custodial parent does not pay child support as it is (correctly) assumed that some of that parent's money will be spent to support the child. The non-custodial parent however DOES pay child support. In actuality, both parents "pay" child support. But it would be silly for the court to hand down an order to your ex to pay herself a certain amount of money each month. So the courts generally rule on means. That is, if each can afford it, then each pays an equal share of the support, which is about $1200 a month. Based on the listed incomes, the Math is kind of easy. Your ex would "pay" $400, and you would pay twice as much ($800) to equal the $1200 a month. Unfortunately, your ex is probably going to argue that she can't afford childcare or health insurance, etc. And the judge will probably buy that argument.
Don't kill me, but I'm betting you get stuck with a bill for $800 child support, $400 daycare, and all the insurance expenses, also. If she pushes for childcare, be sure to have your lawyer ask the judge to cut that (childcare) in half when the child turns six years old, and to eliminate the childcare payment completely when the child turns 12. That is only fair. Yes, childcare is expensive. But how much childcare do you need when the kid is in school full time? And by 12? I was already earning good money baby-sitting younger kids in my neighborhood by age 12...