It's hard to say really. There are concrete examples in both directions I think.
For example, potato cakes used to 50c almost everywhere (10ish years ago), and now they are above 80c everywhere. $1 is not uncommon.
And yet, bread at woolworths has just gone down to 85c a loaf, and 7 years ago the cheapest loaf was $1.16.
I think that once you take into account inflation most things are pretty similar (except housing!).
The real question for me is whether the quality of the products we're buying is the same. Also the ethical and environmental picture behind the products. A $5 t-shirt from k-mart is good value for my dollar, but not good value for our global community.
Probably is buying less but I'm not particularly worried as I notice a leg of lamb isn't at $100 yet and I'm expecting to get a cheque in the mail from the utilities company since the carbon tax has gone. So all in all things are looking really "capital".
I have done food studies on prices and cost since I arrived here in 2009. I still have some receipts from then! Yes most food prices have gone up. However commodities like milk and bread are down. This is a marketing strategy to get the public to shop there. Once in the shop you don't just buy the cheap item...you shop for other things. Meat, fish and cheese the items most of us buy daily have gone up considerably.
Basic clothes in the chain stores have come down a little. Sadly this may have affected the people that have made the garments who live on almost nothing.
For those on a shoe string budget and eligible, seek out your local neighbourhood shop. My monthly pension income is 540 pounds sterling. which equates to around $1000 per calendar month when sent across.
From the shop last week I bought olive oil for $2 a bottle, string of oranges for $2, pandana cheese $2, tomato paste $1 and bread and rolls are free. Almond milk $1 and so on. There are many frozen goods as well frozen before they go out of date. I hope this has helped those on a shoe string budget.