Just driving is pretty expensive. Not owning a car saves loads. Unfortunately, it usually takes a lot of money to live somewhere that doesn't require one.
Also worth noting - my wife would be at home with the kid right now (I have a much higher income) except she has substantial student debt, so off to work she goes. This means paying for creche too.
We couldn't afford creche fees for two kids, and she can't afford not to work due to aforementioned debt.
Also we had a kid because we were approaching mid thirties and it was a now or never thing, but it would have been nice to get a home big enough for two kids (a 3 bed apartment, or a bigger 2 bedroom apartment, would suffice) but the numbers don't add up.