Bananas (about $0.45 each)
One of the most highly consumed fruits in the U.S. (27 pounds per person every year!), bananas are rich in fiber, vitamins C and B6, and, most notably, potassium, a mineral known to control blood pressure. One medium banana contains more than 400 milligrams of potassium, about 13 percent of the recommended daily amount. This versatile fruit is great raw, cooked, or frozen, so stock up the next time you’re in the market.