It's high, we are in a high COL area. We average about $800 per month for a family of four, but it is not unusual to hit $1000 from time to time. This includes all food and household supplies. I know, crazy. However, our eating out budget is about $50 per month, so we are eating mostly all meals at home for this cost.
I pack all lunches for my two school age kids, my husband makes and takes his lunch every day to work. When I was willing to drive to 5 or 6 different stores, our bill was a bit lower (around $600), but the quality of the food was lower. We have decided the quality/source of food is important to us. My husband eats paleo, I am GF, and my kids eat a balanced, healthy diet. We do not rely on cheap grains for the bulk of our meals. Mostly organic veggies, fruits, pastured and organic dairy, hormone-free meat, grass fed beef, as local as possible.
I shop at Costco and the locally owned Co-op, an alternative to Whole Foods, but similarly high priced. We also have our own chickens for eggs, and a garden and fruit bushes which produce lots of salad greens, some veggies, blueberries and raspberries.
Honestly, I am in an ongoing battle with myself to bring these food costs down, but part of me wonders whether I should just relax and accept that it's worth it to us to have this beautiful food. We drive old cars, got rid of cable 8 years ago, have a cheap cell phone plan, and no debt besides our mortgage. Oh, and we still save about 50% of our income.