While some couples have spent tens of thousands of dollars on custody battles, the majority resolve cases outside of court.
Some Kiwis are forking out close to $200,000 on lengthy custody and separation battles through the courts, new research reveals.
But Christchurch lawyers spoken to by The Star say most cases are resolved before it gets to this stage.
The country's biggest study into the issue and how the kids involved coped with different decisions was led by Otago University professor Mark Henaghan.
He hopes the revelations over the costs of New Zealand Family Court battles will shock warring couples into spending cash on their kids, instead of lawyers.
Mr Henaghan led a three-year study with Dr Nicola Taylor and researcher Megan Gallop and backed by the NZ Law Foundation. They investigated the experiences of 114 Kiwi families who fought through the courts over the relocation of their kids, domestically and internationally.
Mr Henaghan said most people knew about the emotional cost of fighting over their kids and the new data would make eyes water over the financial cost.
The researchers sourced dollar figures from 44 of the parents, which revealed legal fees ranged from $2000 to $180,000. The latter fee was spent in two cases and involved both separation and kids' relocation disputes.
The average relocation custody scrap costs about $30,000 for each parent. Put into context, more than 65 per cent of those in the study earned under $60,000 a year.
Researchers were asked to crunch the numbers on how much those in the research spent on legal costs. Even Mr Henaghan was "amazed" by the findings, who remarked: "It's a lot of money: ludicrous."
Family Law Society executive member and Christchurch barrister Gary Collin agreed, saying it was "extraordinary".
But he said the majority of people resolved custody battles outside of court.
"Roughly 90 to 95 per cent of cases are resolved without a family law hearing. In the year ending 30 June 2010 the total number of applications to the Family Court in New Zealand was 67,000. Of these 58,000 were either settled or resolved, while 7000 had some kind of short or long hearing," Mr Collin said.
"If someone comes into my office first thing I do might be send them to counseling, I might write to another lawyer involved or meet round a table and talk to negotiate a solution - a huge amount are resolved before a court hearing."
The study shows people how money can mount up in relocation disputes.
Mr Henaghan said one couple even went to court a staggering 11 times - only for the mother to "voluntarily" end up back in the same city as her ex-partner.
But ultimately the public should be warned Kiwi judges favoured both parties being involved in their child's life - unless there was violence involved.
Mr Henaghan said that with an increasingly mobile society, expensive cases were rising. But Kiwis did not rack up bills like those in similar Australian research, which found one couple spent half a million dollars in a relocation case.
A South Island family court lawyer, Alice Leonard, said the big Christchurch earthquake had spurred several mums, separated from their partners, to relocate elsewhere with their kids. But they had since been advised the earthquake and safety fears were not strong enough grounds alone for such a shift away from the other parent.
Mr Henaghan believed money spent battling through the courts would be better going on travel for the kids, allowing them to spend time with the parent who was not the prime caregiver, and investing in a good computer for contact through skyping and other technologies.
Findings from the research included that 55 per cent of applications to relocate overseas were successful, whereas 40 per cent of applications for relocations within New Zealand were successful. It was mostly the mothers who wished to move (84 per cent) and within this country involved distances from 55km to 1450km. Over a third (38 per cent) of the families fought over international relocation, including 25 from NZ to another country and 13 to this country from abroad.
Countries included Australia, Europe, Canada, Netherlands, the US, South Africa, even Oman and Dubai.
Mr Henaghan said a positive research finding was that no matter what the outcome the children generally adjusted.
He said parents needed to think about what was best for the kids, including the best support and schooling. "If what they're fighting about is not well thought out and well planned, and good for the kids, then they're wasting their time through the court."