It actually gets significantly easier with a spouse, since now you have two incomes instead of one, while the food prices are the only ones that double, and most don't move at all. (Note that this is also one of the reasons why people generally have roommates, or live with extended family.) Kids make it very difficult if you want to live in a single-family household with one working parent on this type of budget, but, again, that's one of the reasons for the (good) social stigmas on divorce and against having children out of wedlock. Take a look at the statistics; being raised with two parents instead of one is one of the best predictors of poverty later in life.
I'm not actually a fiscal conservative (well, at least beyond the deficit). I'd rather that the minimum wage increased a bit nationally (and significantly in high cost of living cities), and I'm a proponent of more collectivized (e.g. single-payer) healthcare. Hell, I'm even a proponent of more collectivized child rearing expenses. But you have to actually live in reality when you're talking about policy.