Anne Mason and David Hall would save $10 a week if fresh fruit and vegetables were exempt from GST.
"Every little bit helps because prices have gone up outrageously," said Ms Mason.
The couple, who live in Hamilton, have two young children and a combined income of about $90,000.
But Ms Mason said it had been getting harder to stick to their household budget and still buy enough fresh produce. "That's always what we run out of ... sometimes I won't have fruit to put in their lunches at the end of the week." They had adjusted their weekly shop to buy produce in season and bake rather than buy biscuits.
The family spend about $75 a week on produce, which would drop to $65 without the 15 per cent GST.
Ms Mason said they would likely put the $10 a week savings into buying more fruit and vegetables.
"Right now it's a struggle to stick to the budget. I think it's a great policy."
But the GST exemption is not enough to fully convince Ms Mason to vote Labour - the family have a second home and she is more concerned by an impending capital gains tax.
"We already pay the GST so we're sort of used to it, so a capital gains tax would be the bigger shock," she said.
Ms Mason works part-time while looking after the couple's children, and Mr Hall teaches fulltime at a Hamilton high school.