I wont bore you with all the facts, but I think the main points…

I won't bore you with all the facts, but I think the main points are that:
- we separated July 2010
- Divorced Nov 2011
- I contributed $36000 at commencement of relationship
- my parents gifted $15000 during relationship (which she is trying to say was used for my business tools, it wasnt)
- we were supposed to paying 50/50 mortgage and private health, however my accountant said I should audit my account, as it appears there isn't enough credits from her to cover the direct debits. So now turns out i have contributed an additional $19000 towards mortgage since separation (which would explain why I don't have any money to pay my tax bill)
- Ex paid for half of private schooling last year, but has not paid anything since (boys were always going to attend private school)
- She earns $76k, and has only been paying $147/mth child support. Our income is comparable, as mine can vary from 70-90k, sole trader.
- we had always agreed to 50/50, I paid a solicitor to draw up a 50/50 agreement in NOv 2010, she refused to sign, i told her to get a solicitor, and it has taken until May this year to receive any correspondence.
- We've received a response back saying they agree to 50/50, but not schooling or medical. my paperwork said if they didn't agree to this we would start proceedings and use our offer to attempt for costs to be paid.
- As it stands, exclusive of business tools, car etc, the property pool is really only the $10k that will be left after sale of house, my super of $30k, and her super of $90k.

I guess I would just be interested in your opinion as to a) what a reasonable settlement would be for out of court, or b) should i just go to court and try my luck. I believe I would receive a greater entitlement due to all of above, but at the end of the day, all I really want is the schooling and out of pocket medical 50/50. I've been told it wouldn't go to court as pool is so small, but mediation of approx $2k a day. Would the court even order that she pay half schooling/medical, or is that when a departure order for child support might come into it?
Just want to know what a realistic outcome could be for me. Tks.