Living on one income and banking the other is certainly ideal, but in reality it may not be possible. In my family's case, our incomes separately have either not reached the self-sufficiency level in our county or barely reached it.
In my county, for a family of two, poverty is in the range of $10,000 and self-sufficiency is in the range of $35,000.
The median household income in my county is $78,218 (as of 2009).
ETA: We have no debt except for a minimal mortgage on an 800 sq. ft. condo. We ended up buying, because rent in this county is too damn high.
