Buy cheap fruit! Around me, that means under $1/lb. BUT - exactly which fruit it will be is going to vary a lot depending on what season it is, and what sales are going on.
Always under $1/lb: Bananas
Sometimes under $1/lb: Grapes, oranges, grapefruit, apples, pears, pineapple, mandarins
Rarely under $1/lb: Strawberries, blueberries, papaya, mango
Most weeks there are 2-4 fruits which meet the benchmark, maybe bananas, green grapes, Fuji apples. The next week it's bananas, red grapes, Pink Lady apples and pineapple.
*The easy-to-peel citrus family: Tangerines, satsumas, tangelos