I agree, great responses. As with many, I go with pasta of all kinds and rice, with meat, poultry and seafood as more flavoring ingredients. It's a bit late in the season now, but next year plant a garden -- even minimal -- one or two tomato plants, one or two cuke vines, a lettuce patch and a couple of hot pepper plants, will yeild enough to keep you through a season for under $10. When you do splurge and go out, always take a doggie bag home. I make an excellent soup with leftover chicken wings.
Fall is coming up, and when the time comes for turkeys to go on sale, if you can possibly make room for a second one, toss it in the freezer. As someone already said, it is great, a super bargain.
If you love cheese, which can be expensive, remember that when you buy stronger ones, you use less. Please don't buy anything you cannot taste. So many people buy those individually wrapped slices. Stop and think. Can you actually taste anything? So much of the cheese that is sold now is actually hydrogenated vegetable oil. Buy a little of something good.
Deli stuff is expensive, but the flip is there is no waste. So go careful there. When you find yourself in possession of something you didn't care for (we have a lot of part timers here, and often they clean out their fridges before leaving, and give me anything that won't keep until their next season) -- look at it imaginatively. For example, I got some ham that there is no way my husband would eat. I trimmed the fat, put it in the food processor with a little ranch, herbs, onion, garlic, and he just gobbled down the resulting spread. Mom used this trick when she got meat that was unpalatable when we were kids and broke.
I do have to watch the budget, but there are a million little tricks. When all else fails, soup for everyone. Almost anything can be made into soup.