Prenup Particulars

Average cost is $2,500 to $7,000, barring the complications of a large fortune.

Like wills, prenups can be endlessly modified.

Sunset clauses render a prenup null and void after a predetermined number of years.

The law regards pets as possessions, so custody agreements about pet care are legally binding. Child custody arrangements are not.

Lifestyle provisions may be included but are not legally binding. A New Mexico couple, for example, stipulated that they have "healthy" sex five times a week, pay cash unless otherwise agreed and turn off the lights at 11:30 p.m.