It's not just about saving money, but saving on time too. Depending on where you are in your life, there's a good chance that your time is at a premium, and you're willing to invest a little extra to give yourself more time flexibility. An awesome goal for any household is to find ways to have both-cut spending and cut down on time spent cooking.
A friend introduced me on her blog to the idea of cooking once, eating for a week. I see the wisdom of this on so many levels. Stock up on what's on sale (Ground beef for example) and cook as many pounds of ground beef you need for however many meals you are preparing. Divide some into the base of a Shepperd's pie, add tomatoes and freeze cooked pasta sauce, add beans and vegetables and freeze a chili for a cool winters day. On nights that you're running behind, too tired to cook, or surprise! guests show up, you have a meal that only has to go from the freezer into the oven. You paid bottom dollar for the most expensive ingredient, and you know EXACTLY what went into your food. There's nothing like pulling out a ready made meal out of the oven and getting that faint whiff of preservatives. Nothing more unappetizing anyway.
Because we don't have a deep freeze, we can't quite pull of the "cook once, eat for a week" kind of schedule. In our household, we usually go by the model of "cook once, eat twice." And I don't mean cook, and have the exact same thing the next night for supper (though the eating of leftovers does happen in our house). We do our best in this house to remodel our meals after they've been served, so it's a completely different feeling the next day. One of my favourites is BBQing two extra chicken breasts when we make any kind of chicken dinner. The next day it becomes a big chicken salad, whether greek, southwest or cesear. Any chili in our home gets remade into sloppy joes the next day, because I love them. When ground beef is cooked it can become a hundred different things with different seasonings.
When I make two meals out of one, my kitchen cooking time is cut way down. When I make two meals out of sale items, I get more bang for my buck. The real test would be to invest in a deep freeze (huney??) and see how far cooking and freezing can take our family.