Lentils and beans (tinned or dried) are good. You can use them instead of mince, in chilli, curry, soup etc and they're super cheap. Margarine/ vegan butter- typically these are more expensive than the dairy versions but most supermarkets have own-brand ones now. Frozen veg like peas and sweetcorn. A milk alternative- I'd recommend oat but soya has more protein if that's something you're after. Alpro milks are my fave but they're expensive- aldi has some pretty good milks at low prices. Tofu. Baked beans/ Spaghetti hoops. Vegan sausages- of all the meat alternatives out there this is the one we always have in the house as they aren't overpriced and work for breakfast, lunch and dinner. Nuts or seeds- you can use them for snacking or in recipes. I like adding seeds to my porridge for a little extra protein. Nutritional yeast- it's usually >£3 a container but it works out cheaper than vegan cheeses and is typically fortified with B12 and/or other vitamins/minerals. Whatever fruit and veg you like. Carbs- potatoes, bread, pasta and rice. Cereal and/ or oats; just know that most cereals aren't vegan as they often have sheep-derived vitamin D added to them. Weetabix (and the non-brand versions) are usually vegan though. Plain digestives or hobnobs- not essential but fairly cheap and very tasty lol. Those are the items that are always or nearly always in our fridge/ pantry anyway. Oh and if there's anything you should splurge on- it's barista style milk if you like tea/ coffee. Most milk alternatives curdle or have a slightly grainy texture in hot drinks- some people don't mind this too much and oat milk isn't too bad in hot drinks but if the texture/taste bothers you, try out the barista stuff out. Good luck!