I'll give a whole-foods perspective, as that is what I follow
; processed foods are what will get you when you're busy!
Chicken breasts can be pricey unless you buy them frozen in bulk; in fresh packs they are the most expensive piece of chicken. Thighs are a great cut that are less expensive and have a lot of flavor; drumsticks are always tasty and easy to cook! Thigh-drumsticks (attached) are good also.
Pork chops are delicious and always pretty cheap; panko breaded and baked they are so yummy! Certain beef cuts are much less expensive than other cuts. "T-bones" "filet" "Ribeye" are all great, but are more expensive; less expensive cuts are wonderful, they just don't have that high-end reputation. Look up different cuts and special ways to cook them, cuts that most people don't buy. Beef ribs are great after they have been stewing for a couple of hours.
Keep fresh or frozen veggies on hand for steaming or pan-cooking (like peas, french cut green beans, snow peas, brussel sprouts, okra, etc.) You can even by pre-cut chunks of butternut squash at the store, which can be cooked quickly and then pureed and seasoned for a great soup. I swear cabbage can be such a time-saver, and it has a long fridge survival time. It's great sliced think and pan fried with apple cider vinegar, dill, and olive oil.
Brown rice, pastas, grits/polenta, quinoa, farro, etc. are all good carbs to include with meals, even canned beans are great, like chickpeas, black beans, cannellini beans and such. Roast chicken drumsticks or thighs seasoned with rosemary, along side brown rice w/a bit of butter, and fresh steamed green beans makes simple and yummy dinner, quite healthy.
Random Ideas: Quick healthy lunches are easy with tuna salad, bean salads alone or eaten with crusty bread, roasted chicken salad made from the leftovers of a whole roasted chicken (easy to buy pre-made at most grocery stores), canned black beans heated up w/spices and onion tossed into a tortilla with tomatoes, cheese, and a bit of sour cream, baked oatmeal w/cream, sugar, and cinnamon for breakfast (make a good bit and eat it for a few days heated up!), boil eggs in advance and eat off those for a few days too. Making and freezing your own raviolis in advance is easy also. At Trader Joes you can purchase little bags of fresh pizza dough for $0.99 a piece, and just throw some sauce/cheese/toppings on for a quick pizza. Crackers are fast and easy to make lots of to have lying around for snacking w/cheese and other toppings- not many people think to make their own crackers, but it's sooo easy and they're tasty (and kept in a tightly sealed container, they last for quite a while) Keeping lots of fresh fruit around will deter you from going for unhealthier snacks like chippies and such.
Oh and toss your chicken carcasses in a pot with some onion and carrots and study while it cooks down, then let it cool and toss it into containers or bags to have stock on hand! Or buy good organic stock to keep around for stews, soups, etc. You can do the same with pork/beef bones.
I highly, highly recommend Deborah Madison's "Vegetarian Cooking for Everyone" because it has tons and tons and tons of veggie sides, sandwiches, appetizers, soups, etc. to accompany meat meals or just to eat as they are. I use that cookbook constantly!
Hope that helps.
