We stayed at the condo that has a full kitchen so to save money we wanted to buy groceries to save money. We had the kids with us so this was convenient. OMG the price of food in Maui grocery stores is expensive. Everything is literally double the price you would pay on the mainland. I paid close to $300 for a weeks worth of groceries that I would normally pay about $150 for. So be prepared.
There is a Costco near the airport but I didnt go to it. I dont know what their prices are like but I suggest to check it out and hope that its cheaper.
What to pay: Double the prices on the mainland.