We stayed in Waikiki, and found a mixture of prices. Eating out was no problem, with a variety of choices to meet all budgets. Our favourite was the Cheesecake Factory, and we even found a Subway for a lunchtime snack. ABC Stores are everywhere, and stock a variety of products, great for Water & Beer.
Yes Hawaii can be expensive, but only if you want it to be, there are alternatives on Oahu, especially if you hire a car for a few days.
I appreciate Big Island may differ, and its such a shame it spoilt there trip.
Kaz.