Week in week out, we've been bombarded with commercials and campaigns spruiking lower prices.

But how do the two big supermarkets compare at the checkout?

A twelve month price check reveals what you are paying now on a basket of products, compared to this time last year.

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In the three months to December, the Consumer Price Index shows:

• tea and coffee up almost six per cent;
• breakfast cereals up about two per cent;
• cakes and biscuits up 1.3 per cent;
• ice-cream up 1.1 per cent.

However the overall price of food and non-alcoholic beverages fell by an average 1.5 per cent.

According to Coles communications manager Jon Church “in the last year it will have been around 6000 products that the prices have gone down on, through our ‘Down Down’ campaign.

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“The amount of price cuts across the store far outweighs those prices where we have put through some cost price increases,” he said.

With this in mind, you would think the price of 42 typical trolley items would be lower.

Excluding the weekly specials and generic brands, here is how one basket of goods from each supermarket compares in price to this time last year.

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At Coles, despite last week’s introduction of ‘super special’ discounts on a range of green grocery items, a one kilo bag of Granny Smith apples was actually up from $4.98 to $5.48.

Heinz baked beans are also more: $1.75 - up from $1.63. And Nescafe Gold coffee has shot up from $6.89 last February to $8.99 today.

However Palmolive dishwashing liquid dropped from $3.19 to just $2.69; Huggies nappies went down from $14.98 to $13.99; and Daily Juice at Coles dropped from $5.79 to just $5.

Yet the overall basket of goodies at Coles is about the same price. Last year the basket of 42 brand items cost $211.31. Twelve months later, it's up just 37 cents.

“It’s not very significant. I would imagine that in the end, people wouldn't have noticed that much of a change, so it’s nothing to be excited about, I wouldn't have thought, or to be concerned about. It’s pretty much stayed stable,” retail expert Paul Harrison said.

For Woolworths Heinz baked beans also rose from $1.63 to $1.75; Greenseas tuna went up ten cents from $1.79 to $1.89; a Cadbury block of chocolate also rose from $4.29 to $4.37; as did a jar of Nescafe from $.745 to $8.99.

Yet Wonder White Bread went down from $3.99 to $3.59; a twenty pack of Smith’s Chips dropped from $6.59 to $5.99.

The products totalled $215.15 last year – yet this year buying the same products would cost you $3 less.

“I think that $3 would be considered significant, particularly if you play it out over a year in terms of the way that people buy things. So $150 saving or so, that's actually quite significant for people who are struggling to get by. I think Woolworths have done well,” Harrison said.

According to Harrison “products cost a certain amount of money to make. You might see generics are being sold for a lower price, but then they have to push the prices up for the national branded items.

“I think the critical issue is the lower prices are coming from the in-house brands, and that's where all the emphasis has been in relation to the two big grocery retailers.”

Consumer watchdog Choice is calling on the Federal Government to appoint a supermarket ombudsman with the power to slap fines on big retailers for anti-competitive behaviour.

Spokeswomen Ingrid Just says “Coles and Woolies have 80 per cent of the grocery market share, and with these deep discounts, there is some concern it could be a reduction in the amount of supermarkets, because the little guys can’t compete with the big guys.”

Meanwhile her advice for customers is to enjoy the discounts while they last. “The real question is how sustainable these deep discounts are.”

Woolworths response statement
Today Tonight’s figures show what our customers know - Woolworths offers the best value in the market.
Woolies customers have seen their shopping bill reduce over the last year, with our prices on a selected basket of everyday items reducing by 3.7 per cent from July to December 2011.
This is particularly evident in fresh produce where we’ve been passing through to shoppers the lower prices caused by the current fruit and vegetable glut.