I don't know since I don't have any kids. But this article, How much does it really cost to have a baby? has some numbers. Here is one exerpt:
"According to the U.S. Department of Agriculture, families who make more than $74,900 a year will spend an average of $289,380 per child over 18 years (this does not take into account college savings). In one year, the average parents spend $4,300 in child care, an additional $1,525 in food, and $2,900 on a bigger home."
That all sounds like alot of money. Some of my students are parents. I am curious to see if you have anything to say about this issue.