Pass it down depends on having a kid around your age that can pass it down to you. We buy second hand for most, but we still have to buy. Yes, there is a need for a larger car when your original car is tiny, or you didn't have one at all. Yes, there is a need for larger housing cause I lived in a one bedroom apartment. As for special needs, I mean, it always can happen, and you always need to be ready that it's a possibility. Telling people that they should have kids regardless then turning around and leaving them with no resources for it is just irresponsible.

You also entirely skipped the most expensive ones. Feeding them, an expense that's been ever growing in the last decade, much faster than inflation. Education and child care, which the cynic in me, having read you say the problems started when women joined the workforce, thinks this is probably cause you think women should stay home for these - I hope I'm wrong.

I'd be extremely surprised if your budget didn't radically change before and after having kids, even staying frugal and living within your means.