Pasta is a great way to eat a filling meal for cheap. For basic pastas such as macaroni, fusilli, spaghetti, fettucine, etc., it's cheaper to buy dried pasta at the store. Barilla usually runs around $2 for a pound of dried pasta of any type, and the store brands are sometimes less expensive if you buy a large package. Filled pastas are usually cheaper to make yourself, since at the store they come with expensive ingredients already inside and need to be refrigerated. The recipe is going to differ depending on what you're making, but typically you'll start with a pile of flour with a dimple in the middle, into which you'll drop a few eggs (and usually some salt or other flavorings). The key is to mix in just enough flour so that the dough is the right consistency, and then set aside the rest of the flour for rolling out the dough. We like to fill our ravioli with a mixture of ricotta, gorgonzola, and parmesan.
A note on cheeses: it's often the case that fancy, expensive "natural" food stores (e.g., Whole Foods, Wild Oats, Good Food Store) will actually have cheaper cheese than the big chain stores. Around here, 5 oz. of parmesan at Albertsons runs you about $6, while at the Good Food Store you can get half a pound for $4, as well as parmegiano reggiano for around $18/lb. (vs. almost $30 at the supermarkets). You'll also find a much better selection. The long-aged gorgonzola we get we can only find at the Good Food Store, and it's only about $3 for enough cheese to last at least the week. Ricotta's rather expensive, but a little cheaper to make yourself. Recipes abound on the web, but the basic premise will be to heat some whole milk, add some vinegar and salt, and let it sit for a few hours for the curds to form. Then you just have to strain it and you've got some home-made ricotta.
Then comes the question of what to put on the pasta. Decent tomato sauce can be expensive, store-bought or home-made, so we usually opt for a bechamel (though gorgonzola ravioli are also good with a pureed sauce of onion and garlic). A bechamel is essentially equal parts fat (I use butter, but margaine or olive oil works as well) and flour to make a roux, which is then cooked for 5-10 minutes to give it more flavor and take out the floury taste. Then you add some milk, bring almost to a boil to thicken it, and then add whatever cheese or other flavoring you want. I always add salt, black pepper, white pepper (for a little more kick without too many black specks in the sauce), and nutmeg (freshly grated is best if you don't want it to taste like Christmas eggnog). For cheese I almost always through in some parmesan, and supplement that with either romano or a mixture of gruyere and gorgonzola. Good additions to any pasta include bacon (mmm...bacon) or frozen peas (one of the cheapest vegetables out there).
