I buy weekly. A typical week (feeding two) would be something like:
1.5-2 pounds ground beef or a whole chicken
5-8 peices of fresh seasonal fruit that's perfect right now. in summer, it can be more like 3 pounds
a ton of seasonal veggies. (basically, when we go to our favorite produce store, we walk out with 2-3 full bags filled with pretty much just fresh produce, 70-80% of it veggies. onions and potatoes and greens are pretty standard. carrots often. it really depends on our menu plan and the season. lately, we've had lots of greens, squash, tomatoes, sweet potatoes, tons and tons of fruit, etc
tomato paste/canned tomatoes (we use this most weeks)
1-1.5 pounds of butter
a quart of yogurt if it's a good price
a pint of cream most weeks
we also buy 2 qt of milk and a dozen eggs most weeks
raisins
nuts
a little bit of cheese for snacking or a planned meal (often feta because it's so cheap)
in addition, we buy things we need to stock the pantry (we don't have a significant pantry, maybe someday:
we buy olive oil every other week pretty much except when we buy it in bulk
coconut oil every month or so
most weeks we buy a few pounds of a grain or legume or two to stock up. (usually we buy what we need for that week, but buy more than we need so we have it around. then buy more when we run low.) this could be chickpeas, navy beans, mung beans, lima beans (my new

), rice, whole wheat couscous, millet, etc
salt
flours (we stock white wheat, whole wheat, white whole wheat, whole rye, whole spelt, sprouted whole spelt, and sometimes others. we have garbonzo as well right now)
whole wheat pasta
It often ends up lasting about 8-9 days instead of the 7 we plan.