It's definitely nice to save a few bucks, and especially so with gas prices being so out of control.

For instance, I like to shop and Sam's Club but if I don't make a pretty large purchase the extra savings gets swallowed up by the cost of driving there in my V-8 pickup (yeah, I know- it's an evil vehicle but I can't afford a Volt!

). But I do try to get lettuce and veggies there- I get 'em in bulk and vac them into smaller bags. I find that I'll eat a salad almost every day if I have lettuce, but if you don't seal it it usually goes bad before it can all be used up. And if I vac broc or cauliflower into single serving bags with a butter pack and some seasonings all I have to due it nuke it for a minute and I've got a nice side dish with no waste.
One super cheap thing I really like is
Shin brand ramen. Honestly, there are restaurants that don't serve noodles this good! They're about $1 a pack vs the 10/$1 price of the cheapest ones but are much, much better. They're all carbs so I don't eat 'em very often but they're a great comfort food item to me.
I really like to buy whole pork loins. Around here they're usually $2/lb or less. Generally I'll either roast the whole thing or cut it in half, roasting half and making chops out of the other half. My standard method used to be to season with Montreal Steak Seasoning and roast @ 325 til the internal temp is 134
o F, but the last couple times I've cooked the loin sous vide. The SV one will be much more juicy and tender but both are excellent- a true feast for not much money. Plus, you can thinly slice it up and simmer in BBQ sauce for some heavenly sammies.

In addition to simply being low cost, some of my favorite things are large batches. Since I cook for a living and attend school, I like having something I can nuke/prepare quickly. One of my favorites is to brown several pounds of burger and make taco meat. Then thru the week I can make taco salads or tacos. For a taco salad I like shredded lettuce with some onions and feather shredded cheese. For dressing I mix sour cream and salsa half and half, blending them separately in a small bowl. To me this makes a terrific dressing and it's pretty low carb (assuming you get salsa that's not full of sugar).
Where I live you can get Joseph's Lavash breads in several local stores. A four pack is under $2. I like to brush them with olive oil and season with garlic, salt and Italian seasoning and back them on a cooling rack til they're fairly crisp (about 4-5 min @ 350
o F). This makes a great personal pizza crust! It's actually a bit much for one, and usually I'll just use half of one if it's just for me. At any rate, they're great with conventional pizza toppings, but often I'll make a chicken & onion ranch pizza with them. Just cover the crisped up lavash with ranch dressing, then top with mozzy & diced red onions. I then add thinly sliced chicken breasts that I've cooked sous vide (generally 140
o F for an hour and a half, followed by a chill in an ice bath). The lavash happen to be very low carb but even if you don't care about that they're very, very tasty.
Eggs are always good for a cheap meal. I always say if you have eggs and either onions or cheese in the house you've got a fine meal. I like to whip mine with a touch of milk or water and some Tobasco. When I cook onions go into everything except chocolate cake and banana bread, so I always add them to my eggs!

Certainly some cheddar or pepper jack is great on an omelette, and a bit of chipotle or adobo salsa in the middle and over the top is sublime.
Soup is a classic low cost, large batch item! On occasion I'll make cream of baked potato soup...that's probably about my single favorite comfort food. Ham and bean is also good. Chicken noodle or chicken rice is also a winner. They all the advantage of being cheap and using up things you often have one hand. And of course, after Thanksgiving it's a given that I'm going to make turkey soup!

But few soups can match the value and stick-to-your-ribs goodness of chili. The nice thing is that you can use about any cut of meat and make it more as a soup or more of a meal. I'll make it with ground beef, ground pork, chuck steak, italian sausage, pork sausage, round steak, pork loin...or any mixture of the above. I think adding beans makes it a better value and more filling; beans add a lot of protein and fiber, and you'll need a lot of meat if you don't use beans for some filler.
Cassoulet is another good, inexpensive meal that can be be pretty rustic or downright elegant depending on what you include.
Around here, chicken legs and thighs are pretty cheap- and luckily for me, I much prefer them to the rather bland and semi-tasteless breast meat. And if you wanna splurge an extra few bucks for some wine and fresh mushrooms you can make Coq au Vin with them! French food gets no better IMOHO. One thing I'm really wanting to do eventually is a sous vide version of Coq au Vin...
Spaghetti and meat sauce is another classic that happens to be pretty cheap. I will very often use canned sauce and doctor it a bit with some herbs, especially in the summer. Some onions, some mushrooms if you have them on hand and some meat will make a very hearty sauce. Burger is fine, hot italian sausage is better. I like to make mine basically into an Arrabbiata sauce with some crushed red pepper flakes.
Growing up tuna and noodles was one of the cheapo foods we really liked. It was pretty much shell macaroni with cream of mushroom soup and tuna in it. I still like it today, provided the pouch tuna is used.
A grilled cheese is a great inexpensive treat. I like to use shredded cheese. It's extra good if you butter the bread and press it into a plate full of grated parmesan cheese before grilling. You get a very nice nutty, cheesy crust on the outside and gooey cheese on the inside. It's extra, extra wonderful if you have some cream of tomato soup with it...
One last cheap-and-lazy sammi that can actually make a decent lunch is a triple decker PBJ. If you have good bread and Jiffy it's a real treat for me.
I'm fortunate to have a sous vide cooker, a cast iron dutch oven and a pressure cooker. Armed with any one of these tools you can really make the most of lots of different cuts of meat. A chuck roast is sublime cooked in a dutch oven. A pressure cooker will let you make amazing stock from bones in about half the normal time, and can be a good way to cook tough cuts of meat, too.