What would you do differently if you knew your grocery bill was about to double? Would you change how you shop, where you live, what you eat?

South Islanders don't need to imagine it anymore. They're living it.

In 2024, the average South Island household spent $15,305 on groceries. Twenty years ago, that figure sat around $7,500. The bill has doubled in a generation. (Source: Stats NZ, food-price-index-regional)

But here's what makes this moment different: half that increase happened in just the last five years.

In 2020, South Islanders were spending $12,509 on food. By 2024, it hit $15,305. That's a $2,796 jump in four years. Compare that to the previous 15 years, from 2005 to 2020, when the increase was roughly similar but spread across three times as long.

The velocity changed. What used to happen gradually, over decades, is now happening fast enough that you can feel it year to year.

Break it down to weekly terms: that's an extra $54 a week since 2020. For a family on a tight budget, that's the difference between making rent or dipping into savings. It's the reason KiwiSaver balances are shrinking. It's why consumer confidence keeps hitting record lows even when unemployment stays stable.

The steepest climb came between 2022 and 2023, when the grocery bill jumped $1,329 in a single year. That was the peak of the inflation surge, when supply chains were still recovering and fuel costs were spiking. The 2024 increase was much smaller by comparison: just $241. The worst of the acceleration might be over.

But the damage is done. Even if food prices flatline from here, South Islanders are now permanently spending $2,800 more per year than they were before COVID. That money has to come from somewhere. For some households, it came from entertainment budgets, holidays, savings. For others, it came from debt.

The question isn't whether your grocery bill will double again. It's whether wages, benefits, and household incomes can keep pace with the doubling that already happened. Because right now, they haven't.

Every time you load up the trolley, you're spending roughly twice what someone in your situation spent in 2004. And if the last five years are any guide, the next five won't be any gentler.