My budget is $160 pw. For ages we were going over anywhere from $10 to $40, but lately I have been under. That is due to our veggie patch finally being productive and we now get milk from the local farmer in exchange for eggs. We also eat the odd rooster of ours and have chooks for eggs. We spend about $10 per week on chook food, so technically that should be added to our food budget costs.
One pack of $20 nappies is included in the shopping once every 4 weeks. There is also the usual toilet paper, washing powder etc.
We cook most things from scratch, most bread is out of the bread maker. No expensive cereals, I make a batch of bircher twice a week.