Get 1 large chicken and roast it for 1 dinner with potatoes and veggies (I tend to roast veggies - butternut squash can be very good value, with an onion, and some carrot if you have it, any leftovers make great soup seasoned with nutmeg OR chilli).
Leftover chicken at least 2 more nights - ideas include stir fry (noodles or rice), risotto, with tomato sauce and pasta, with freshly boiled potato and veg (chick reheated in leftover gravy if you have it), curry, creamy sauce with mushrooms, fajitas or burritos (or plainer wraps) etc. For only 3 people, you should get at least 2 if not 3 dinners of leftovers and possibly one lunch of sandwiches as well.
(Could also boil bones and veg peelings for stock to make soup or risotto).
Lidl do a pack of "cooking bacon" which is quite good value. Can be used in tomato sauces with pasta, quiches, scrambled eggs, macaroni cheese (with added veggies like mushrooms/courgette/peppers/onion/garlic/peas etc if you want), pasta carbonara. You'd easily get 3 dinners from 1 pack.
1 lb of minced beef would make enough spag bol or chilli con carne sauce for 2 nights of dinners, just add plenty of veg to the sauce when cooking. I tend to make up 2lb of beef at a time, feeding the 3 adults in the house and freezing sufficient for 5-7 individual portions for other nights (I use takeaway tubs recycled, so they are handy for stacking in freezer and hold a single portion per tub).
Eggs are great - do a fry for dinner, make quiches, scrambled eggs/omlettes with fillings (mushrooms, bacon, onion, tomato, peppers, grated cheese etc), use for a carbonara sauce with pasta, do poached eggs for breakfast/lunch...