you can eat reasonably well if you know firstly how to cook, not just a spag bol, but know what cuts of meats are inexpensive, for stews, casseroles, potatoes for mash, roast, or boiled doesn't cost a fortune, and veg if you look in shops like sainsburys or markets, a bag of carrots in sainsburys for a pound, that is not dear, so it is sometimes a necessity to start with the basics, you don't have to be a cordon bleu chef, but have an understanding of how to cook... and what will go far.