Those same friendly people who brought you the Food Pyramid have been tracking the cost of raising a child since 1960, and not surprisingly, it's more expensive than it was then, and moving forward it will be even more expensive.
The latest Department of Agriculture child-rearing study--Expenditures on Children by Families--reports that a two-parent, middle-income family (with income from $56,870 to $98,470) can expect to spend $221,190 (or $291,570 when adjusted for inflation) to raise a child born in 2008 over the ensuing 17 years, or from $11,610 to $13,480 per year, depending on the age of a child.
The USDA's Center for Nutrition Policy and Promotion says that a family with income over $98,470 can expect to spend $366,660 to raise that child. By the way, this does not include the cost of a college education.
The full report, and an online calculator to determine the cost of raising a child in your clients' hometowns, is at www.cnpp.usda.gov.