re: How much child support should I expect to pay?

LA support schedule

You are responsible for 63.5% of the child's welfare based on you and the future ex's salary. The formula for the state at your combined income level says you should be spending $1325 per month on the child. You are responsible for 63.5% of that which is $841.38 per month. This does not include costs for childcare and medical costs. Add those costs to the $1325 per month and multiple by 63.5% and you should get pretty close to what you will have to pay.