NEW YORK (AP) — Donna Brown visited a Whole Foods for the first time in at least five months with one goal: see how much Amazon had cut prices. She did buy almond milk, yogurt and lunch meat, but doesn't plan to quit her usual grocers, Walmart and HEB, where she says she finds bigger selections and lower prices.

"I am a comparison shopper," says Brown, a part-time administrative assistant in Austin, Texas.

Amazon made a splash right away as the new owner of Whole Foods, slashing prices Monday on baby kale, avocados and ground beef. That attracted some customers, but whether shoppers who've fou...