I’m with you. I think there is definitely fudging numbers going on there.
Things like the mortgage and taxes are going to be the same no matter how many people live in the home. The utilities are just a matter of adding the extra one more person uses to the base cost of having them and two adults already using them.
Hand me downs work for clothes. A child does not need new clothes every time the fashion industry changes styles.
Nor do they need a constant supply of new games and toys.
Exactly what I was thinking.
My wife and I had bought a 3 bedroom house even before we had children. We ended up having 2. But the point being, we bought that house and would have lived in that house, whether we ever had children or not. The children living with us did not increase the mortgage or property taxes or maintenance.