I too agree that too many parents use money as an excuse not to have children. However, there are indeed other costs involved in raising kids that parents do need to take into account.
Not everyone has reliable medical insurance through their job. Even when people have medical insurance, they often don't have dental insurance (or good dental insurance.) We have had three children with orthodontia (about $4000 each - they had some pretty severe problems that were *not* "just cosmetic." Bad genes...), and insurance only paid about a fifth of it. Some insurers pay nothing. Routine dental appointments every six months run about $75 to $100 each.
We don't go overboard in any way with lavish lessons, but we do have some children in some assorted lessons, and they aren't cheap either.
Then there is college spending. Ours are exploring low-cost alternatives, but if you own your own home and aren't divorced, and have anything saved for retirement at all that's outside of IRAs, don't expect any "need-based" financial aid.
...that's why I included the caveat about health bennies.
Here in Michigan, all children have access to insurance--period. If insurance cannot be provided by the parent, it is provided by the state. Another thing to consider, which, sadly, most people don't: Doctors, dentists in particular, are some of the most willing negotiators you'll ever find outside of a farmer's market. They won't bring it up, but its true. My advice...shop around. Call three different dentists a day, explain your financial situation and the needs of your kids, eventually you will strike gold--probably sooner than later. Most doctors will offer a reduction of fees to the uninsured or underinsured if they are asked to do so. Many will allow you to pay off expensive dental work on a payment plan with no interest--you pay what you can afford to pay. Depending on how often your kids need to see a specialized doctor, you might want to consider contacting the closest state university (or any other college) that has a medical/dental school--it may mean driving an hour for an appointment, but if your appointment is only once every two or three months it could be cheaper in the long run.
Its far easier to negotiate with a doctor than a corporation!