We are "price sensitive" and buy almost no processed food. We used to buy much of our 'staples' (basic items such as milk, flour, sugar, tissues, toilet paper, etc.) shopping from Aldi. We would then have to go to Woolworths or Coles to supplement with items which weren't in Aldi's range. This saved us quite a bit of money.
Coles used to be cheaper than Woolworths, but that seemed to have reversed a few years ago and we started to buy mostly from Woolworths after our Aldi shopping.
A seismic shift occurred when Woolworths started price matching Aldi's products and it became just as cheap and more convenient to buy everything in one shop.
Then, to make it even better, perhaps a year ago our local Woolworths stores started marking perishables down as they approached 'best by' and 'use by' dates, and, doing more discounts. Conveniently, they keep their mark downs together, so they are easy to find.
We now buy up on the discounted items such as dairy products and meat, and freeze them until we need them. This way we are still within the life of the product. The result is that we spend even less on perishables.
In our area Coles mark down too, but not nearly as much as Woolworths, and they keep the mark downs in their original locations. This makes it harder to find, and they often get covered up by non-discounted stock.
Selected Aldi stores have started marking down some of their stock items like bread as well, but this varies tremendously from store to store. Most don't seem to mark down their perishable stock items at all, they just remove 'use by' & 'best before' items on the due date from the shelves.
What we have notice though is that it is the budget lines in both Woolworths and Coles seem to be diminishing, being replaced by more expensive lines. Sometimes it is done by rebranding and repackaging homebrands, other times the budget home brands just disappear. When I have enquired, they don't know why, it is just what they have been sent. All in all, it seems to be getting more expensive to buy food.