I compared grocery prices at Walmart, Kroger, and Amazon using Walmart's recently price-dropped items as my guide. Savannah Born Walmart recently dropped prices on over 250 items, so I took a closer look at nine of them. I compared their prices to what I found at competitors Kroger and Amazon. Amazon didn't impress me. Walmart had the lowest prices, and Kroger was close behind — but I may have gotten lucky. When Walmart announced rollbacks on more than 250 items, my ears naturally perked up. T