Cost of living in Brisbane can vary depending on where you live. The lion share of the cost goes into accommodation rent. Usually, you will pay AUD 360 for an apartment in Brisbane per week. Among the rest is the utility bills, food, cleaning or laundry, internet, phone, and transport.
You will need (per week):
AUD 90 to 135 for groceries.
AUD 40 to 60 for water, gas, and electricity.
AUD 20 to 40 for internet and phone.
AUD 25 to 40 for transport on a student discount.
The figures here are average cost. This can greatly change depending on the number of people sharing with you. More people have a higher total cost but can be less when divided. But you also have to make sure everyone pays on time.
There have been many cases where flatmates do not do their chores and do not pay a dime. This creates a very big problem later and even fights ensue. So, you have to keep the cost of living in Brisbane in mind.