South Island's largest supermarket will open early and under budget in Christchurch's Rolleston

With 485 carparks and 250 staff, the new Pak'nSave Rolleston,is forecasting more than 30-thousand shoppers each week.

Foodstuffs South Island's retail and property general manager, Tim Donaldson says it's been built for under 50-million-dollars and will open in October - two months earlier than expected.