well are you sure that its not just the quality of his diet thats better like more whole foods, less processed. i hear you need to stay away from things containing cottonseed oil, because this is often not used in food rather used in clothing it often is grown with much more pesticides than food is.

Look for a farmers market in your area. Depending on where you live, im sure there are some around you. You said you live in the country , so there should definately be some good farmers markeets around. Just keep your eye out and im sure you can find cheap and great organic foods.

Here is a great article about spending less for Organic foods:

growing your own is a big step towards spending less. Learning how to put up the excess for the off season (winter/spring) is the next very important step. I suggest buying some books on putting food by. has an excellent selection of such books (and gardening books too-the salespeople are long time serious organic growers so pick the best books out there).

You will need canning supplies (a canner, jars, lids/rings), a chest freezer and at least one dehydrator. You might want to find a Freecycle group in your area and ask if anyone has any of these items and also start looking around at auctions/e-bay/yard sales.

Find a farmers market in your area and start going regularly. Buy in bulk in season. You can great deals on cases of produce that you will take home and preserve.

Yes it is a lot of work but you and your son will know exactly what you are eating and you will save thousands of dollars per year.

On your garden if you have never done a garden before keep it small and grow only things you know you like and don’t grow space hogs like sweet corn which you can get cheap at the farmers market.

Meat will likely be the most expensive item and the best way to get the price down is to buy sides of beef and hogs and put them in a freezer.