Today, for example, I carried what seemed like an uncomfortably heavy set of bags, yet it only came out to about $30, and will probably last me the rest of the week: 2 lbs pork tenderloin (2x $5), 5 lbs potatoes ($3), 2 lbs tomatoes ($4), 1 lb lentils ($3), 2 lbs onions ($2), 1 head broccoli ($1), 12x eggs ($3), 2 lbs nectarines ($3).
I think I more often run into the problem of buying way more than I can carry/eat, and it still doesn't cost much. I mean, I like nectarines, but 2 pounds of nectarines is a lot to finish before they get overripe, so some of that might get wasted. But since they cost me damn near nothing, that's alright.
Cook them! Throw them in a pot with some brown sugar and spices. Or throw it in a crockpot/baking dish with {1/2 c. butter, 3/4 c. flour, 3/4 c. (brown) sugar} sprinkled on top, bake, and shazzam! Cobbler!
While the way we eat is certainly an outlier (and I know it), I'm equally as sure that you are too.
I spend around $200/mo on food, $250 tops, in Manhattan. Mostly yummy healthy stuff from Trader Joe's.
Or did you mean $500/mo for two people?