You don't indicate how large your family is but I now have a family of 5 (3 teen boys, 1 grown man and me).
I can do a huge salad for cheap if I buy the greens myself and cut everything up. We always have the ingredients for some kind of salad dressing because I have a variety of oils and vinegars on hand with various seasonings. I tend to pick up what is on sale to throw into my salad so it is different everytime but yummy and filling.
Beans are tasty and can be economical when cooked from their dried state. You need to soak them for hours before rinsing and cooking but again they are super yummy.
Soups created from what ever you have on hand in the fridge thrown into a stock pot or crock pot with some veggies, potatoes, and/or rice.
Gravy over rice is always sweet. Anything you cook which has liquid save that liquid for making gravy. I love gravy.
Potatoes (white or sweet) are divine inspirations that can be tricked out in many ways. Don't be afraid to be creative.
Rice - another staple to any great diet. Advance from your usual traditional white rice and move toward some flavored rices like Basmati or Jasmine rice. These are great with chicken, fish or pork.
Often I get away with only using meat to flavor foods instead of being the main thing about the meal. This is hard with guys but since I'm buying the food and cooking the food, I get to have my reign.
Pasta goes a long way and so does humus.
Get inspired and step out of your usual box and try some new things you never tried before. We love eggplant, bok choy, soy, tomatoes, olives, onions, potatoes, greens (all kinds), peppers (all kinds), ginger, garlic, cucumbers, celery, parnips, turnips, etc. Don't be afraid to try new recipies along the way. Have fun, be creative because it doesn't have to cost a fortune you just have to be prepared.
FYI - I switched us from jar spaghetti sauce to hunt's or delmonti in a can. It is more economical for the same amount and tastes great. It seems to be less watered down than it's jar contained competition.