Being of father of two, with another due in November (my third boy!), I can say that in the early years the cost of raising children is overstated. The biggest expense will be diapers and formula once you have the basics (kids' furniture, clothing, etc.), and if you've got a fairly sized family on both sides, it seems they're usually very generous when the first kid comes along.

I think the "knee jerk" reaction is that people think they'll be run into poverty by the cost of raising a child. Remember a few important things...infants don't
need to wear $50 Tommy Hilfiger sweaters and $40 Nikes. And spending top dollar for everything you buy your kid doesn't necessarily make you a better parent. Some parents, regardless of their finances, tend to go overboard on frivolities.
That being said, I think alot of people also try to squeak by too tightly regarding their finances. The extra cost of a child can't be absorbed because they're already living "hand to mouth". While you're young, eliminate debt, particularly high-interest accounts such as credit cards, personal loans, etc.. I personally would rather be paying another car payment for a tangible asset than a $250-300, 19% APR credit card payment.
As previously mentioned, try to buy some type of property for a primary residence. The tax savings are tremendous. All of the mortgage interest and real estate taxes are tax deductible. A $1000/month payment really only costs you $600-700/month because of the effective tax relief.
If you've got your car now...keep it. If you're making payments, by the time you're married, you'll own it. Then it'll be time for another toy.

I've been fortunate to have a career that has positively progressed. I had the same concerns ~8 years ago. Now at 33, I live in a nice house, have 4 cars (the TR, my GT, a '99 Taurus daily beater, and my wife's new '03 Suburban Z71), plan on moving into a bigger house in the next year and am putting money away for my kids' education.
Good luck.
S.