So, $25,000p.a. is ordinarily low enough to qualify for Legal Aid, but I tend to suggest getting Legal Aid funding through a private lawyer, rather than through Legal Aid directly.
For our family, self-representing just for the parenting matter cost us about $1,700 (not including things like printing, copying, transport, all the usual things that lawyers charge for).
The biggest expense once in Court was actually the fee for the first day of trial, which was $590, and I believe it's $590 per day thereafter. We also spent I think about $410 on filing the initiating application (interim and final), and another $110 on an application in a case. The initial mediation, before we knew anything about family law, cost $600 to have a lawyer present (and frankly, the outcome from that mediation was atrocious).
During proceedings, we took advantage of Legal Aid's free consultation regime when we needed legal advice. They offer three free consultations for a single family law matter, and we found them very helpful - they provided templates, advice on what we needed to file, guidance for how to conduct cross-examination, and scanned over our affidavits to check they were okay. We also sought out I think one or two free initial consultations with private lawyers, mainly to get a view on whether a proposed change to the orders we were seeking would be viable or not.
Without going into the ins and outs of the thing, there were three mentions, one major set of interim orders and two minor sets, one mediation session and orders for both parents to attend a post-separation parenting course, then the matter ended up settled by consent for 50/50 about two weeks before the first trial date.
We avoided the costs of additional trial dates, a family report and appointment of an ICL. There was also no property settlement attached, so avoided costs of valuations, etc. Although rife with the usual complications (allegations of abuse, etc.), the parenting matter was essentially a fairly straight forward matter because the other parent's affidavit stated the child had a healthy relationship with both parents and both parents participated equally in care duties from birth.
All in all, the child came away with a great outcome, at a cost of about $1,700 to us, and about $20,000 to the other parent.
My husband self-represented from end to end, but ironically, we had decided between ourselves that we would get a barrister to represent him at trial because he was not confident about going before the Court alone.
The next day, he received the first proposal for consent orders and a frustrated text message from the other parent complaining about the cost to her of going to trial when it was going to cost us nothing because we were self-represented. Had she known we were going to pay for representation at trial, I'm certain that we would have ended up in Court for a hearing, so we dodged a bullet there.
The best way we kept costs down was by doing everything ourselves until we were facing trial. We could communicate with her lawyer directly, so it didn't cost us anything to forward proposals for settlement while proceedings were afoot, but we still enjoyed the benefit of legal advice from Legal Aid and others.
But with that said, it comes down to confidence. Obviously, my husband benefits from having a wife with a law degree and lots of experience from inside a law firm, and I do try to share some of that here, as well, but getting guidance on the legislation is one thing. Actually drafting affidavits, filing forms and attending Court is another.
Your friend benefits from you having that knowledge and experience, so in my view, self-represent at least until trial. Since 95% of initiating applications end up settled by consent, it's not likely he'll actually have to attend trial, anyway.