Legal Aid offers family dispute resolution conferences, as does Relationships Australia and most family law practitioners. A family dispute resolution conference is mandatory before a party can commence proceedings in court.
If you can reach agreement by consent, the cost is minimal - about $155 in filing fees, I think - but if agreement can't be reached and one of the parties applies for parenting orders to be determined by the court, the initial filing fee is $320, plus $110 for interim orders (which you will definitely want), plus whatever the cost is for legal advice or representation, etc.
While proceedings are under way (they can take several years, which is why you want interim orders to be put in place at first mention for the duration of proceedings), the parties are encouraged to continue trying to reach agreement. If the proceedings continue to trial, the cost for each trial day is $590, plus the cost of legal advice, representation, etc.
About 95% of parties that commence proceedings for parenting orders end up settling by consent and without trial, so those costs are kept to a relative minimum.