yes, it is expensive.
we spent -- for a family of 3 -- $320 per week, and that does not include household items. so, just over $100 per person. It should be noted that my husband and son have very fast metabolisms, so they eat a fair bit more than "normal" people of their age, weight, etc.
that being said, we live in NZ, where food prices are higher. in the US, some of our friends spend less than $50 per week on themselves, utilizing processed bulk foods at costco with coupons. but, we haven't eaten that crap in years, and were 100% organic and free range while we were in the US, and our average weekly amount (for two, with DH eating like two people) was $200-250 per week, not including household items. So even there, we managed to get it down to $100-112.50 per person.
Here is how I saved money:
1. join a CSA (community supported agriculture) -- they often have "scholarships" for families who quality. Lots of fresh produce, enough to "put things by" for the winter months. you have a bit of a "luck of the draw" with what they produce, and what's growing that week, which is why learning to put things by is essential. you also have to introduce a lot of new veggies, but it's a good option for local and organic foods. over summer months, you might get TONS of produce for about $300 for the month (depends upon the cost of the share).
now, to be sure, I did not do this. We could never trust the box. We do this currently (local, organic produce -- $80 per week and it usually lasts us about 10 days PLUS we supplement with some grocery store picks that come from australia and other parts of NZ. So, we felt ready to take on the "christmas-surprise" aspect of these boxes. But, friends of mine in the US were local members of CSAs and got fruit, veggies, herbs, nuts, and fresh flowers from their CSAs every week, and it worked well for them. It also gets you eating seasonally!
2. organic may not be that important to you, nor might local, at which point you might consider finding a veggie whole-saler. In our early days, we utilized one (before going organic), and I would get A LOT of fresh produce for about $30. Something like "bag of 8 apples, $1" so, i would get salad greens, veggies of all kinds, all kinds of fruit. It was usually the stuff that wasn't purchased by grocers or restaurants because it was bruised or very ripe. we might loose a couple of pieces of fruit or one or two veg by the end of the week due to mold, but the rest of it was ripe and flavorful.
i think that for large families in particular, this is idea. you can also call a local, commercial supplier of produce (like a restaurant would use), and ask if there is such a place in your area. if so, then go there.
Seriously, it's a good deal. Summer before we moved here, I was eating cherries and berries like a fiend -- 2 lbs of cherries for $1! You can't go wrong. And, a friend of mine helped me freeze some and make jams and so on. Good stuff. I ate it all!
3. grow a garden -- indoors or out -- for expensive things like micro greens and herbs. we are just starting our herb garden now, and it makes a HUGE difference. herbs -- dried or fresh -- here are very expensive. we tend to buy in bulk (when buying dry herbs and spices), but it is still expensive. i like flavorsome foods. So, we are growing our own herbs. We really don't have a lot of garden space, so we are using pots and doing our best with the space (and sunlight) that we have.
also, learn to put some of this stuff buy (drying, keeping in oil, making pestos, etc). this is something that i'm learning as well. martha stewart has great recipes for keeping herbs.
4. bone broth, offal, and cheap cuts of meat -- or buy half a cow -- all of these are ways to increase nutrition and decrease cost. you can also buy a fair bit on sale, and while grass fed and finished, pasture raised is "optimal," the fact is that it's better to eat what you can afford that is within the primal WOL/WOE and not worry about this so much.
we currently find ourselves eating more beef, venison, fish and lamb because it's a LOT less expensive than chicken here. We get 1-2 chickens (whole) per week, and make bone broth from the bones once we've picked off all the meat -- but otherwise it's just too expensive to have as frequently. the rest is a lot less expensive. and, we get 'off cuts' to make things like osso de buco - which uses the shin bone -- and you get marrow, meat, and bone, and then can render the bones AGAIN for stock. which is fab.
we use the stock to make soups (which extends any meat -- we eat a lot of soup), to steam veggies, to make egg drop soup for breakfast (extends eggs that way, we use fewer), and sometimes just as a nice, warm drink. And, it's very nutrient rich.
Doing these things can greatly decrease your food costs, and you have to really experiment to see if you can get it down to $100 per person -- and possibly less. I think it can be done and buying less processed foods really does save money. There are never coupons, but shopping around, looking for the best prices, etc -- makes a big difference.