In my quest to be healthier, I've tried to become more aware of what I'm eating and what's in the food I'm eating. Awhile back I came across Ali's site at cleanerplateclub which has been a wealth of knowlege and resources. She recently posted about the expense of eating healthy, and how it's exponentially cheaper to eat unhealthy, processed foods than it is to eat organic/fresh foods. I'm only able to shop at Whole Foods about 50% of the time (due to (lack of) proximity to the store, not really economic factors) so I don't see much of a change in my food spending. I do, however, notice a significant increase in the quality of the food I come home from Whole Foods with. Potatoes in my local (and very creepy) grocery store are often literally 1/3 the size of the ones I get at Whole Foods. I like knowing that I'm coming home with food that's "cleaner".
I feel extremely lucky that, though not rich by any standards, I am financially able to choose my food and even my cleaning products based on companies whose business practices I support and those that are environmentally friendly. Whole Foods donates 5% of their profits to not-for-profit and educational causes and they cap their executive salaries based on the average of all employee salaries (it's still a high number, but the fact that an excecutive salary cap exists at all is amazing), and Method cleaning products are environmentally friendly and non-toxic.
I recently picked up a book called Twinkie:Deconstructed by Steve Ettlinger. He took each ingredient listed on a Twinkie wrapper and dedicated a chapter to explaining what it is, where it comes from and why it's used in foods. He used the Twinkie because it contains the most comprehensive list of ingredients that are commonly used in foods. It's an interesting read if you are at all curious where the components of food are derived from or why "beef fat" is listed as a "possible" ingredient in Twinkies.