You could buy a whole bunch at Walmart, then make a monetary donation to a food bank or medical emergency fund or homeless shelter to help the folks who work at Walmart make it on the low wages and lack of benefits.

I lived in a little town that got a Walmart. It was pretty devastating. I've become a bit of a passive activist (is there such a thing?). I try to buy stuff only at places that pay living wages and give decent benefits to all employees even if it costs me more. I figure if I'm getting something cheap at Walmart, it's only because I'm ripping the food or medicine from one of their employees for the lower price.

Guilt. Guilt. Guilt. And I'm not even Catholic...