A trolley of 17 popular school lunchbox items, including yoghurt pouches, cheese slices, Vegemite and multi-pack chips, is most expensive at IGA, costing $100, according to consumer advocacy group CHOICE.
Coles and Woolworths followed closely behind, with baskets priced at about $90, while the best value was found at Aldi at $75.
That is a difference of $15 between the supermarket giants, without factoring in any sales or promotions.
"When including specials, Aldi was still the most cost-effective option, with their full basket costing exactly the same at $75.98," CHOICE Editorial Director Mark Serrels said.
"Woolworths again came in second, with a basket costing $89.08. At Coles, the basket with specials cost $90.09, and at IGA the basket came in at $99.10."
The consumer group also calculated the cost of a smaller shop containing only school lunch products, again finding Aldi to be the cheapest at $41.
Items included baby cucumbers, blueberries, ham, tinned tuna and sultana packs.
Cost-of-living pressures are continuing to hit families hard, with one in three Australian students going to school each day without lunch, according to charity Eat Up.
That figure surged by 24 per cent in the past year, with many children relying on the charity for regular meals at school each week.
According to CHOICE, the average cost of a basic basket shop, which included bananas, strawberries, apples, carrots, milk, chicken and Weetbix, rose by seven per cent between March and December 2025.
Strawberries have seen the most price volatility across the year.
Milk, chicken and carrots had the smallest increase in price and apples rose the most, increasing 47 per cent between first and fourth quarterly surveys.
