I buy bulk chicken thighs and breasts when they are on sale. I bake a big batch of chicken thighs at one time on a baking pan in the oven. Brush on a little olive oil, some salt, pepper, a light dusting of onion and garlic powder for flavoring, or some curry powder, and just bake. Eat some then, wrap the rest in foil for later. Or part it out and freeze some.
Same with hamburger meat. Whatever they have on sale that day. Not on sale? I don’t buy hamburger. Same with pork chops. Buy bulk, cook bulk or portion and freeze.
Eggs are cheap. You can go for the gourmet designer eggs if you want, but basic old eggs are still about a buck a dozen.
Most low carb vegetables are also inexpensive. Squash, bell peppers, heads of lettuce, spinach. Avocados are often a buck a piece. Asparagus, broccoli, and cauliflower can get a little pricey but still cheaper than meat.
Nuts can be expensive, but you need to limit your portion size there anyway, so wait until they are on sale and stock up.
I like almond milk. It is generally cheaper than organic cow’s milk in the same size carton. I buy plain unsweetened Greek yogurt in the big containers. They last a while - portion size is key there again.
I buy whatever berries are on sale that week (blueberries very rarely). Usually either strawberries, raspberries, or blackberries. Not on sale? I’m not eating berries that week.
I have never bought ghee. When I cook, I use any or a combo of avocado oil, olive oil, or butter. They all last me a long time.