Russet potatoes have a shelf life of several months when kept in a cool, dark place with good circulation, making Costco’s 10-pound bag for less than $5.00 a great buy.
Costco onions may be cheap, but they need to be stored away from other produce in a cool, dark, well-ventilated space, or a portion may go bad before you can use them.
When properly chilled, citrus fruits have a long shelf life, about three weeks to a month, so there’s no reason not to take advantage of their cheap price at Costco.
Costco sells tomatoes on the vine at a slightly lower price than average, but these are often unripe and won't develop their full flavor even if left to ripen.
Storing carrots in a cool, dark environment will keep them fresh for several months, so Costco’s inexpensive giant 6-pound bag of carrots is an incredible option.