How much your divorce will cost depends on you.
You have to stop thinking, "but it's mine because I paid for it", "I want revenge" , "I do not owe him or her anything because s/he left", or "its the principle of the thing". If you do, you will end up with an unpleasant and epensive divorce process.
Divorce proceedings are very hard for everyone involved. If you cannot do all of this in one attempt, take several tries at it.
Many parents get stuck on the title of being the custodial parent. The legislature has changed the law, removing the title of 'custodial parent' and, instead, calling it an allocation of parental responsibilities. No matter what you call it, what it means is who spends time with your children, how they see both of their parents, and how parents make decisions for them. The reason that some parents get stuck on the title is because they think that being the custodial parent means that they get child support. Other parents think that sharing the kids 50/50 means they will not have to pay support. Neither of these is true. There are cases in which the parent with more time pays support to the other parent. There are cases in which the parents share time, and one parent still has to pay support. Finally, some parents want the title of custody for no other reason than control. They think if they have custody, they can determine if their child sees the other parent and when. This is not the truth either. Having custody of your child is not the opportunity to control them. Children need both parents. Think about your children, what they want, and how to ensure that you can both be a part of their lives.
If you can settle your case, do so, even if it does not turn out quite like what you wanted. There are several different ways to resolve your divorce issues. Mediation is an excellent way to reach an agreement without going to court or hiring lawyers. Collaborative law also allows the spouses to work together to make decisions about their children and property division. Besides helping with the stress of the legal process, these methods take less time and save you a lot of money that could be better spent on something else like affording child care, your children's college or your future.
If you think that you cannot come to any agreements with your soon-to-be-ex, the average attorney charges about $300 per hour. You will pay for every call and email. Lawyers.com suggests you will spend $11,000 or more getting divorced. I have outlined a typical divorce here. And with all of that money going out, it is possible that you will end up with nothing or very little.
What most people actually experience is this: hiring attorneys to get the Court to resolve every issue creates more stress than it relieves and it takes longer to finalize your divorce than you had expected. Attorneys are expensive and you are letting someone else decide your future.