About 80% of my shopping is done around the perimeter of the store and I can tell you exactly the order that the items hit my cart as I travel around the perimeter:
That gets me to the front of the store and from there it's just a couple of trips into the aisles to get a few canned goods and oatmeal. No frozen ready-to-eat entrees, no chips, no cookies, no processed cereals and other junk like that. Almost always under $100 to feed family of four for at least a week.
I do get one thing in the frozen section and that is frozen blueberries and blackberries. They taste great when swirled into plain vanilla yogurt, much cheaper than fresh and don't have to worry about spoilage.
By picking them as fast as they ripen they will keep putting out new berries. Two small bushes will give you over a quart of berries a week for months.