Divorce360.com calculates it this way. The average American family, according the Census numbers, is married, has two children, makes between $50,000 to $74,999 a year and owns a home worth about $185,000 - though the home value varies enormously by location. This family would spend more than $50,000 on lawyers, counseling for themselves and the kids, and the many costs of selling the house and moving.
Contested divorces cost much more - easily twice the amount of an uncontested divorce.
And that depends on being able to sell the house. MSNBC reports, mostly on the basis of anecdotes but probably accurately, that divorces are down at the moment because unhappy couples can't afford to sell their houses or charge the other services they would need.