> If I buy groceries at Walmart or another discount grocer, my bill is nearly half of what it would be if I shopped at a "nicer" supermarket and well over half of what it would be if I shopped at a place like Whole Foods.

I like to do both.

We don't have a Whole Foods, but there is a small regional chain here that has organic local produce and grass fed antibiotic free hormone free meats and such.

I use Walmart for things like 2 liter soda bottles, frozen vegetables, lunch meats, bread, condiments, paper goods, and the like, and so save money compared to places like Safeway or Fred Meyer. I can then justify going to that small regional chain when I want a steak or fresh produce and buy their expensive grass fed beef and the locally grown organic produce.