If you have $200-250/ week left after your rent is paid you should have more than enough for food and everything else you need, but of course you have to live accordingly.
The maximum amount for student allowance (citizen/ resident, not to be paid back) at the moment is $250/ week, the maximum amount available for living cost (parents over income threshold and has to be paid back as part of the student loan, again resident/ citizen) you get even less.., and not everyone has parents that can or will help with costs, so lots of students have to pay rent plus buy food etc. with that amount, which means they need to find a job to support themselves.
I am not saying it is a huge amount per week what you will be getting, but it is definitively manageable.