Here are a few inexpensive and somewhat unconventional methods of getting real food on the table.
The first is foraging. That is going for walks and picking up for free what nature provides. The most obvious is wild berry picking, almost every green area in north has some form of
native edible species. Rose hips, saskatoons, black berries, fiddle heads, mushrooms (Be careful), dandelion greens (Still considered a delicacy in many places. The first time I ate them was at a fancy restaurant in a salad.) and everyone who has a lawn has those growing, they are good for you and free as a bonus. Here in CA we have avocado groves and oranges and lemons and limes and pomegranates. It's criminal to take fruit from someones trees, but ground fall is legally fair game. My father in law takes an empty backpack with him when he goes for walks near his home and comes back with avocados, oranges, and loquats that he spotted while walking. He's also made friends with some other neighbors and gets himself lettuce and picking privileges on some of their trees. When I lived in Kelowna I would wander through the orchards and take home fallen apples and those were the best tasting apples I've ever had.
I found this handy list a while back when my children found mushrooms and wanted to know if they were edible. It's a list of dozens of foraging and ethnobotany sites.
Second is the fact that bulk buying is cheaper and that whole grains are healthier. Ordering in bulk on line and getting your own grain grinder to make flour can save you a lot of money in the long run, and you never run out of flour. Or if you live in the grain belt take a short trip to your local farmer or grain elevator and find out if you can purchase it there. Let your fingers do the walking. My in-laws, when Y2K was in the air even got an electric grinder that could be converted to run off of a bicycle in case they ever didn't have electricity. There are also several things that don't require a mill that are cheaper in bulk. Information on storage, use, and sources of bulk foods is readily available. I liked this place the rest of the site was fun to read as well, and this.
I forgot to mention community gardens last time. There are several cities that allow public land, to be used as garden for urban dwellers. You usually have to apply for a plot and wait for one to be assigned. Also, when gardening in colder climates with shorter growing seasons you can start your seeds inside which is cheaper than buying bedding plants. Also learning how to harvest seeds in the fall keeps you from needing to purchase seeds more than once, and you can trade them for other varieties as well. This is also very political as big seed companies are making seeds that only produce one season so that growers need to buy seeds every year and are lobbying governments to make seed harvesting and exchanging illegal in an attempt to make the world dependent on them for food and drive prices up. Harvesting and trading seeds these days amounts to a political protest.
The last thing that I'd like to mention today for those who can't afford to buy fresh produce is to check the clearance bins at your local Whole Foods type store or fruit stand. You will usually find things that are about to turn and haven't yet, they'll be organic and good quality but overripe or soft and need to be used right away and so they'll be deeply discounted. My children love it when I find strawberries on clearance, they almost always become popsicles and smoothies. Bags of tomatoes become homemade tomato sauce and soup, apples turn into pie and sauce, peaches can be eaten write away and then cut and frozen or canned. Mushy peppers are roasted peeled and pureed for adding to soups and sauces. Potatoes become soup, Much can also be done with a food dehydrator, and one that works without heat is better because more nutrients are left alive.
I thought I was done and then I remembered that I have whole wheat egg noodles in my cupboard that I paid $0.40 for at family sized bag Big Lots. Most of the stuff at the dollar store and Big Lots is crap, but not all of it so it's worth stopping by to look for things. Take your label reading skills with you and practice saying no firmly before taking your children along. Explain to them what you are looking for and why. They can turn out to be good at spotting things worth getting and you are teaching them valuable skills as well. And no matter how cheap it is don't buy Kool-Aide unless you need an inexpensive die for yarn or crafts.
For more ideas on life on a budget including meals here are a couple of places I visit often. Meridith at Like Merchant Ships had a cooking contest a while ago with another blogger on how cheaply they could make dinner. They called it the Iron Chef Mom. She also has a frugal blogroll that links to several others doing the same. The New Homemaker has articles covering every home related subject including gardening, cooking, and making ends meet. They have just published a recipe book of crock pot cookery as well for only $7.95.