Kids aren't that expensive if you don't take them to daycare. Mine wear hand me downs, I bought their furniture on craigslist, they don't eat much and can't tell name brand from generic, we do tons of free stuff (library, parks, etc.), bought a $70 year long family pass to the KC Zoo which can knock out 3 hours any nice day.
There are ways to not go broke, live on one income, and still have nice things for the kids. Those who say different are working for Babies R Us.