Whole foods and Walmart are on the two farthest ends of the price/quality spectrum. Aren't there any main-line supermarkets ini your area?
You can rely on Kroger, Safeway, etc. for standard items such as dated milk, packaged sliced ham, oatmeal, and common fresh fruits and vegetables such as apples, bananas, and red bell peppers, where you can judge for yourself how fresh they are.
Only go to Whole Foods for the occasional specialty items you like. A lot of what they sell is purely "snob appeal".