Can the Federal Government Require to you buy something?

One of the premises of the argument against Obama's health care plan is that the Federal Government requires you to purchase something. At first I did think this might be a bit dubious, however, as I start to amass goods for the Future Baby, I'm suddenly dumbstruck by all that I'm mandated to purchase.
I have to purchase a car seat to get the baby home. I guess I could take the bus or walk, if I didn't want to. That is also like saying we don't need to buy food. How many Americans are able to grow their own food supply?
I have to purchase vaccines in order for my child to participate in society. We are all familiar with the fight on this front.
I have to provide a quality environment for the baby. If I don't buy diapers and let it stew in its own waste, Child Protective Services will come take the baby.
I must provide clothing to the child, or it will not be able to leave the house. Again, I might be able to raise cotton, clean, spin & weave it into cloth from which I can then fashion a garment, yet that loop hole is a bit silly. So, the purchase of clothing is required - especially if my child is to attend school. If my child does not attend school, I'm mandated to provide education for it - which requires the purchase of curriculum/materials, etc.
It seems silly to say that the government cannot require us to buy things.