Like Springbett, millions of people are looking for ways to save on their groceries, with around a third now shopping at multiple stores to find the best deal.

Finder money expert Rebecca Pike told Yahoo Finance Costco’s primary appeal was offering lower unit prices on items sold in larger quantities.

“Costco's bulk-buying model can offer significant value on certain items, particularly for larger households or those willing to stock up on non-perishables,” she said.

However, she said it was still worth doing your own research.

“It’s also important to remember that not every item will be the cheapest, so you should really be clear on how much the unit price is at your local supermarket so you can compare,” she said.

Bulk buying also won’t be practical or possible for every household, including smaller households, those with limited storage space and those who don’t have the upfront cash to bulk buy.

“It’s essential for consumers to be savvy. You should be really certain that you can recoup the membership fee through savings from your bulk buying, and that includes having the means and the space to do so,” Pike said.

“If you don't shop there regularly, or don't buy enough to offset the fee, it might not be worthwhile.”

Costco membership worth it for Aussie mum

Springbett said the grocery savings, along with the savings she gets from her and her husband filling up their cars at the Costco fuel station, made a membership worth it for her.

“It has definitely changed my perception a little bit on Costco. I can see that value more clearly now, but also I will be inclined to purchase more things in bulk,” she told Yahoo Finance.

Costco allows members to bring up to two guests and Springbett said she often takes friends and family members to help add more value.

Springbett usually shops at Coles weekly and spends between $100 and $120 for her family of three. She then shops at Costco every few months and spends about $200 each trip.

She said the biggest items she likes to buy at Costco are school snacks for her son, fruit and vegetables, which can be frozen, and loaves of bread that can be frozen.

Springbett said she was very “strategic” with her Costco shop and made sure she wrote out a list and stuck to it.

“You can get distracted. You can go in and everything looks shiny and exciting … You can end up walking out spending $500 easily,” she said.

“The excitement of Costco is quite appealing, but that doesn’t benefit you in any way if you’re spending double the amount you intended to."

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