I spend on average 400-500$ a month for a family of four-six. (We get company a lot via my sister and her husband or my baby sister's boyfriend.)
When I was living on my own, I had to look for ways to have the foods I needed without them going badly, or cooking too much at once, etc.
I wrote in another thread about superfoods and the importance of them. If nutrition is important to you, than identifying which foods help you the most can determine your grocery bill.
Some things I used as a lone cooker:
- Brown rice. It keeps well (I keep it in the fridge, it lasts WAY longer there because it has a bit more oils in it than white rice) and it's easy to cook up and serve with anything. Also, good for you and filling. Samurai warriors were a fan of brown rice for it's nutrition, flavor, and quick long-lasting energy. I think it's a great way to start off the day..
- Whole wheat pastas are easy, quicker than rice even, and are versatile. You can literally put anything in pastas, and store brand versions are cheap now a days.
As far as veggies go:
- Eat the rainbow. It's a catchy phrase, but accurate. Get all kinds of different veggies. What I did was buy the frozen ones, because they last so long, and custom created mixes that I liked with different meals. (So I had asian mixes and italian mixes, etc.) They also come pre-mixed. Frozen veggies are wonderful and quick.
- Peanut butter with omega-3's in it rock, and when it comes to breads, when I lived alone, I put most in the freezer and kept just a few slices out overnight to defrost in the old sandwich bread plastic so it wouldn't dry out while defrosting. Bread keeps well in the freezer and in the fridge if you eat it a lot but not fast enough for the counter.
- Eggs were mentioned earlier, but I totally believe in them.
- Beans taste like whatever spices you put in them, and are SO easy to cook in a crock pot and they're really cheap. Lots of nutrients, and you need your legumes.
- Spices can offer a lot of different tastes with the same kind of foods, so keeping a couple varieties of choice favorites can be an easy way to mix up the same old routine. Or, if you're like me, hot sauces will satisfy any bland blahs.
An emphasis on veggies and complex carbs with the right amount of protein will keep your grocery budget down. Learning to cook for one isn't so hard either. Usually I did a routine of cooking for two meals, and putting the half of dinner away for lunch the next day. So I never felt like I was ALWAYS cooking, and I had fast sandwich fixings and some healthier frozen things in the freezer for days I had no time/was lazy.
I also recommend learning some crock pot recipes. Those require no work at all, taste great, and are an easy way to cook things like beans and meats. You can set the next day's meals for overnight and enjoy them with no effort really.
If your grocery is like Kroger, and do manager specials on foods about to expire, you can get really awesome usually expensive things for cheap. Sometimes I get some awesome premade salads (usually $4 a pop) for $1.50 - $2, and get to try new things. If I buy those things, I consume them usually that day or the next.
These are my tips

Versatile ingredients, a variety of colors in veggies, and multi-nutritional veggies, fruits, and meats and grains will keep you on the right track.
NOW! On to cooking all that shit you just bought.
If you have/get a crock pot, the only thing you have to remember is to have liquid in it. A can of broth, or a can of soup, water, anything really. To give an example of a recipe:
- Dry package of beans
- Twice the amount of liquid as you have beans (broth or water)
- Any meat you want in it (chicken, leftover meats, steaks, porkchops, HAM HOCKS

)
Put it on low, and cook those things overnight together. A couple hours before you want to eat it, you can add frozen veggies to thaw and cook or rice, or just eat it as the beans and meat they are.
It's a simple recipe, and you don't need beans in there. Liquid + anything = crock pot.
- Pan frying is easy.. any meat like chicken pieces, you can put a bit of olive oil in it and cook the meat over medium heat until when you open the chicken piece it's white in the middle and all through it. Frozen veggies are easy to add to pan-frying as well, you just cover with a lid and let it steam themselves hot.
- In the oven, you can cook almost anything on the bake function. Chicken breasts, covered in some shake-n-bake can go in the oven until done in the centers. You can also create casserole leftovers out of rice, soup, and any leftover veggies/meats you have by combining them all in cookware and putting them on a bake function.
- Finally, the internet is the best cookbook you can own. Don't bother buying a bunch of cookbooks until you know what you like cooking. Find recipes you like, then you'll know what to buy out of convenience.