I have noticed a post about the living comparison between Beijing & Melbourne, probably it's useful to outline Sydney expenses too :-D

ASSUMPTIONS: Working couple with 1 child (household income A$105k, 3 yrs working experience)

Mortgage Repayments Monthll $2,200.00
Strata Monthly $242.00
Local Council Rates Yearly $660.00
Water Rates Monthly $50.00
Electricity Monthly $50.00
Gas Monthly $50.00
Telephone (Home & Mobile) Monthly $120.00
Car Registration Yearly $750.00
Car Repairs - Maintenance Yearly $500.00
Vehicle Insurance ($1000 access) Monthly $72.00
Groceries Monthly $250.00
Meat Weekly $50.00
Eating Out Weekly (lunch only) $100.00
Child Care Monthly $1,300.00
Hairdreser/Barber Monthly $20.00
Holidays/Travel Yearly $2,800.00
Credit Cards Monthly $250.00

All expenses sum up A$67,758 per annum. After tax household income A$80,280.

Some stats:
39% expenses come from mortgage (32.9% income)
23% expenses come from childcare (19.4% income)