This info is based on my personal experience living in Sydney outskirts, approx 45 mins from city.
Rental prices vary according to Area but in the 3 years we have been here it has increased greatly, rental prices can be anywhere from approx $800.00 to $2000.00 a week for a standard 3 bedroom.
We find the train service fantastic, have only ever had one late train, and a few track work occasions but they provided buses in lieu of, price from North Sydney e.g. Hornsby to Central one way approx. $5.00 peak $3.37 off peak
Buses are more likely to be late, both networks run on an Opal card which you can have an automatic top up set up so that your card never runs out of credit. You just tap your card to get on and off and it automatically deducts the amount on completion of travel.
Loaves of bread can vary between 0.70c to the branded products of $4.00 a loaf.
Milk approximately $4.00 per 2L
For my family of 4 made up of 2 adults and 2 teens we spend approximately $200.00 per week on groceries which we could do cheaper but we like some 'treat' food.
With a Medicare card we have yet to pay for a doctors visit but things like X-rays etc you do need to pay for. All prescriptions we pay for but I find the price not to bad.
Public school fees vary, for Year 8 student the years fees are approx. $700.00 but you need to add to that stationary, any extra uniforms and some excursions or camp fees that may occur.
Petrol for my car is approx $30.00 a week but I'm not having to travel as far as a lot of people to get to work.
We average $200.00 a month for electricity
Landline Phone and Internet is $75.00 a month for unlimited data and use of landline but all calls are extra.
My mobile plan is Optus, $30.00 every 28 days for 500mb, unlimited texts to Optus users, unlimited calls to Optus users, 250 mins to call standard Australian numbers, voicemail and 23 selected countries while in Australia and unlimited data for use on FB, Twitter, My Space, LinkedIn,eBay and Foursquare, and $30.00 credit to use for other.
Coffee or hot chocolates range around $4.00 mark depending where you buy from
Movie tickets adult approx $20.00 Student $16.50 Child $15.00 but some mobile companies and movie cinemas offer reduced priced tickets for members.
Temperatures can range from too damn hot to bloody cold, in this past month we have had 40*c days down to 18*c with an occasional hail storm for good measure.
Sydney in particular can have extreme traffic congestion, better to travel outside of peak hours or use the train.
I have been here for nearly 3 years and love it but would happily move back to Asia as we miss the food and the cheap cost of living there. Could not see myself returning to NZ as I find it now too small after living in big cities elsewhere and have heard recently that the cost of living there has risen as well and become quite expensive.
Hope this info is helpful to anyone looking at relocating to Sydney.