I was going to suggest chilli, as well. And if the meat is expensive, we usually just have it with kidney beans and no meat. We use this recipe quite a lot, and also this one. This one also looks good. I find that the great thing about chili is that if you make a lot of it, you can keep the rest in the fridge/freezer and serve it up again a couple of days later.

I am also a big fan of CheapSoup (which is what we call it in our house), where you basically buy a load of the veg off the selected seconds/quick sale (I don't know what the US term is, but the bit in the supermarket produce section where they put all the stuff with bruises and sell at a markdown) and make soup out of it. I usually chop half an onion, fairly small, gently fry it off in a little bit of oil, add the veg (carrots, swede, turnip, parsnip, celery, potatoes) dry and let them fry off for a little bit, and then add some stock (by which I mean water and a stockcube) and let it all simmer until the veg is nice and soft. If I'm using other veg (there is always aubergine (umm, that's eggplant in the US, right?) and courgette (which is zucchini?) then I add those a bit later because otherwise they go a bit too mushy. Salt and pepper to taste, and any other herbs, and just keep it simmering until ready. You can also cook a half-cup of rice in it, which bulks it up and turns it into a hearty, warming meal.

I am also a big fan of pasta bakes with potato in, for extra filling and warmth. This recipe is a Nigella one, and thus full of expensive ingredients. Every time I make it, I use regular supermarket pasta (their own brand, but it also works with their value brand), and whatever cheese was on sale - it does help to have some of it be a softish one, but it's not actually compulsory, a clove of garlic (or the pre-pureed stuff if it's cheap enough) instead of the garlic oil, and dried herbs instead of the sage.
(Now I've made myself hungry!)