The real costs of kids are the necessities. Child care, clothing, food, medical & dental expenses.
I live in the midwest and send/sent my children to a daycare that is extremely price conscious even for this area. It cost me over $7000 per year per child. So when I had 3 kids in day care at the same time; I was paying $21,000 a year just for daycare. For some people that is not sustainable; it is as much or more than they earn.