21 ounce box of Cheerios for 5.69 is worth it. For the 17-ounce box of special k, the price per ounce is 4.89/17 = $0.29 For the 21 ounce box of cheerios, the price per ounce is 5.69/21 = $0.27 The box of cheerios is a lower price per ounce and the better deal.