This is another evidence of the widely known fact: cook your own meal is far cheaper than eating out.
The cheapest food I've found here is Panini in Precinct, £1.90
It's large, it's tasty, but the parlor doesn't open at night (doh).
Compare the cost of eating out with buying groceries, it's pretty damn cheaper! Hehehe.
I've also tried a whole week only eating homemade sandwich, it could cost slightly cheaper than cooking rice and simple dishes. But... For now, I need my Indonesian food :)