[Illusion]

See I love white rice, so I buy a box of instant rice. Costs 5 bucks for a box packed to the brim (no plastic bag FYI which is awesome)
I put a cup full in a bowl it pretty much fills my dinner. (I tend to have 2 cups) the box is hardly even dented after a week. It lasts a long time and fills you. Why do you think the Japanese eat it all the time?
Just buy quantity not quality, don't buy fruits they don't last. If you buy fruits buy the big sacks of them that cost way less. Eat vegetables lots, they last and are extremely cheap.
Spaghetti/Pasta is extremely cheap meal that fills a family you just need noodles and sauce. And ground beef if you want meatballs.
Don't buy juices/pop, they don't last. You want something to drink? Tap water, or milk. Go easy on Milk its very cheap but it lasts. Eat the off brand cereal its healthier and cheaper.
When you want meat think small, get ground beef and chicken. Its cheap, never buy chicken off the bone they give you less meat actually then chicken breasts and by the time you compare the pricing chicken breast costs way cheaper then chicken on the bone. And you can do a lot with ground beef, just don't make anything that require buns AKA hamburgers, ect. Bread costs at weird prices, the only bread you should buy is the 1 dollar dinner loaf that you throw into the oven and cook.

Well I'm stopping there xD (I could go on...) If anything I said interested you try it.