I fail to see where in the original article it mentioned any costs relative to parenting. So turning this to talk about the costs of single parenting seems a non sequitur.

also, when you say 7.25/hr is not a living wage, I think you have to take into account the location. In NYC you are right. However in many parts of the world this would be considered a very good wage. Cities generally deal with this by raising the minimum wage within the city, something I think is a very good policy.

Btw, in my original example I wasn't living in a rural area.