Sorry you're housebound
@Woolfold, that can't be easy for you. I'm practically housebound as I'm a carer for by husband, so I rely a lot on Tesco, Asda, and Ocado deliveries. I have a delivery from one of them once a week, ringing the changes for variety and because prices do vary. I know delivery costs of foods come into play, but I balance that out as I save on transport costs. As I tend to buy most of my groceries from Tesco I've joined their 'Delivery Saver' for £5 a month for off-peak deliveries.
It's pretty easy to read the nutrition labels of foods while sitting in your favourite chair at home perusing carb content, and scouring for bargains, stocking up when products are on offer.
I store quite a bit of winter veg in the frost free garden shed such as carrots, onions, cabbage, cauli, leaks, celeriac, swede, it's surprising how long they can be stored during the cold winter months. The freezer stores meat I bought on offer, normally it's bacon, sausages, cuts of chicken, fish, mince and stewing steak. Obviously there's the tinned stuff (tuna, tomatoes... ) that's pretty easy to store. Cheeses are nearly always on offer and they easily store in the fridge for quite a while. Eggs can sit at the back of a kitchen cupboard for well over a week. Milk, butter and cream manages to last over a week in the fridge.
From my POV, seeing that I don't buy cakes, confectionary (except Lindt 90% chocolate bars), biscuits or anything made with flour, the savings made make my low carb way of eating very economical.