The one overriding element in most family law matters is the presence of anger. The other spouse or partner was too cold, cheap, lavish, flirty, obstinate, abusive, quick-tempered, lazy, strict, unforgiving, generous to others, intoxicated, outgoing, shy, unsuccessful, or too quick to pull the trigger on the marriage/relationship. They have always "disappointed" the other in some way. In the majority of cases, there is always lingering resentment which hinders and delays the parties from settling their differences regarding custody, visitation, division of assets, and the other myriad issues that arise when couples separate, either after a marriage, or having children together.
I have been practicing Family Law in Massachusetts for 34 years, and the two primary factors in determining how expensive a divorce or child custody matter will be is:
1) the complexity of assets to be divided; and
2) how angry is one or more of the parties at the other for the other one's 'faults' or actions.
Many parties become unreasonable in their positions with each other because they think the Court will "punish" the other side once they prove what a "bad person" the other partner is. They are looking for vindication in the relationship. They should look elsewhere. The judges and the lawyers don't care, although a few lawyers (no names mentioned here) will take advantage of that anger to drag the case out and charge more legal fees.
Do your kids and your wallet/pocketbook a favor and leave the anger out of the equation. If you need vindication, get it from your family, friends, and counselor. The Courts are only concerned with the best interests of your children (as you should be), and dividing property and making support orders that are fair and equitable. They do not declare a 'winner', nor will anybody else. The best thing you can do is put your children first and move on with your life.