Maybe the local groceries have their prices online that you could show your husband? Or even just the sale items, with the sale prices compared against regular prices? If he won't look at the screen you can still read it to him.

And the slow cooker is your friend. You can get better tastes from cheaper cuts of meat. Condensed soup and big pieces of beef and onions, for example. Potatoes and frozen vegetables.

Oatmeal was another thing I get when I am really low on money. Get bulk oats if you can. A bit of salt, butter, and cinnamon are enough; it doesn't really need sugar. 2:1 water to oats, and it only takes about five to ten minutes to thicken if you add boiling water to the oats and let it sit. It really does taste a lot better than the packets of instant oatmeal.

You may be able to grow things like lettuce, onions, and garlic indoors. Bell peppers are easy to grow outdoors, and so are jalapenos.

I have trouble keeping food costs under $10 per person per day most of the time. That would be more like $1500 per month in your family. Someone who hasn't been to the grocery in over a year would have to see it to believe it.