Well you can ignore it as long as the marriage goes well :-) but in a divorce the court will make it very clear just how much money the marriage cost the higher earner, both in terms of dividing up past earnings, and in terms of dividing up future earnings via alimony and child support.
What the court imposes is more of a penalty on divorce, than a representation on what a wife costs.
For instance, we used to make a little money when I married my wife, now we make a lot more. We didn't change our lifestyle or spending, nor what we spent on the child. Just savings increased, none of which we planned to give to the child. But now the child support calculator says I owe a lot more after a divorce, which is supposed to be money for the child. If the cost of the child didn't go up, it makes no sense the child support would go up when you earn more money, but it does. It's just a penalty on whoever earns more or doesn't take the child, as societies way of getting even for violating Christian norms.
But a penalty for one side can be viewed as an incentive for the other side. Which given either side can initiate divorce, could increase the divorce rate.
