I don't know if you're a rich guy planning to marry down in the social hierarchy, living in a culture where where women don't work or just a misogynist but this is generally false in the west. Dual incomes with a single household is very economical compared to life as a single.

See eg. http://www.investopedia.com/terms/d/dinks.asp "A household in which there are two incomes and no children (either both partners are working or one has two incomes). DINKS are often the target of marketing efforts for luxury items such as expensive cars and vacations."

If your wife expects you to support her financially. Fortunately, such arrangements are no longer mandatory.

Depends on what else you're getting out of the arrangement.

A spouse might already be a sunk cost.

That’s right, you are not going to get any one cheaper to change your adult diapers. HA!