Diapers run us $40-50/month. usually 6-7/day are used and they cost $0.20. Add in wipes and creams to get the range right.
Medicine is about $5/month, thats Gripe juice and childrens tylenol; about all we needed.
Accessories were under $1000 for crib, stroller, bedding, extra blankets, a backpack to carry diapers, car seat etc.
RESP - (university education in Canada) is $200/month for 12 years (then I stop)
Childcare is roughly a persons annual salary for your area, divide by 3, and then divide by 12. As the child gets older, it goes down, its a lot easier to care for 4 year olds then babies (so the ratio of kids/provider changes). So If I expect my daycare person to make $36k, my portion is $1000/month. Childcare is a service job, they need to make a living wage, in HCOL it will obviously cost more then LCOL areas.
Currently, my little tax breaks don't cost much, the refunds cover quite a bit. I get child cheques in Canada that range from $0 if you earn $200,000 to $6K if you earn $30K (amounts based on income). Government support is very high in Canada, what does Australia have?