This week's survey showed a year-on-year price drop at Countdown Fraser Cove of $3.99, while Gate Pa New World's basket increased by $6.51 and Pak'n Save Papamoa's rose by $2.16.
The Pak'n Save and New World brands are owned by Foodstuffs NZ. Antoinette Shallue, communications director at Foodstuffs NZ, said the results underlined Pak'n Save's claim to the nation's lowest grocery prices.
"We are delighted that the results of this survey have shown how Pak'n Save is continuing to deliver on its promise of offering customers New Zealand's lowest food prices. With reference to New World, our goal is to always remain price competitive with the market. Prices do fluctuate between stores, based on specials, but we will be reviewing the list of products tested to ensure we're delivering great value to our customers in every corner of the store."
Luke Schepen is national communications and public affairs manager for Progressive Enterprises, owners of the Countdown brand. He was delighted the survey showed Countdown's price for its basket of goods had dropped.
"The survey highlights the fact that Countdown shoppers are enjoying great value and prices at our checkouts, and we'll even pack your bags. While the survey just looked at 20 products, we have a huge range of products and thousands of specials every single week where savvy shoppers can find great deals."
Budgeting expert Lyn Webster, who runs her own budgeting advice website www.pigtitsandparsleysauce.co.nz, said getting the best value for money was more about the shopper than the supermarket.
"I did a similar test once when I went into three supermarkets and compared prices. The thing I discovered above everything else was that it isn't the supermarket prices which are the problem, it's the shopper.
Take a tin of spaghetti, for example. You can either buy an expensive brand or you can buy a home brand tin for 75c. All the major supermarkets have their own home brands, and they're all perfectly good products, so buy those instead. There are millions of alternatives, and the cost savings add up."
Ms Webster advised caution when confronted with multi-buy deals which seemingly offered value for money.
"I'm against coupons and the so-called deals. They are just steering you towards products and purchases you wouldn't otherwise need or buy. Don't get sucked in by all the advertising, just avoid it. It's designed to get you to put your hands in your pocket.
"Also avoid products with excessive packaging; not only are you paying a large sum for the packaging, it's also bad for the environment."
There are tactics for people to keep their shopping spend in check, she said.
"Write down your shopping list and stick to it. People don't need a lot of the things they put in their trolleys. They have all the excuses under the sun for a $300 weekly grocery shop, but really it's all about self-control. Get into a different mindset and keep control of your spending." For those who wanted to go a step further, Ms Webster said it was possible to limit a weekly grocery bill for two people to just $35.
"There are two people in my household and we live on $35 a week. Everyone can do that.
"We clean our teeth with baking soda, wash our hair and bodies with baking soda, even make our own moisturisers and deodorant. It's easy when you know how."