Fresh food and why I'm not allowed to eat it (sometimes)

Seeing as how I'm a student living on a meager budget I'm forced to live on the bare 'student essentials diet'. This consists of such fine food as black coffee in the morning, KD at lunch, and fast food for dinner. This really makes me appreciate what goes into a good meal. But more then that it makes you wonder, 'If you're paying more for food that was grown and prepared well, what are you getting when you buy the other stuff?' Now everyone knows that a hamburger you get at Hero Burger is going to be of better quality, and better for you then the squeeze out ground beef that they serve at McDonalds.
While I am forced, because of my budget constraints to eat alot of grade-c protien, I would like to know that even through it is of lower grade that it is still just as safe for me as the triple-a cut. My concerns have been recently highlighted in Bitter Harvest and Fast Food Nation. Take a walk in these books and you'll start to see, just as I am, that the food we eat, whether fast food or in a restaurant, is not a good for us as we once thought.
Im seriously thinking about trying this 100-mile diet that the good people at eatlocalchallenge.com have suggested, but it just seems to impractical to me to go out and do it. I value my body and that is why i try to eat as healthly as possible and excerise as much as i can. However, how does a person find the time to go shopping in local markets all the time and pick out only local foods when they sitll have a variety of other commitments to deal with. I only have to contend with school, clubs, and a part-time job, but how do the people with a family, work, and a full time job cope? Seeing as I don't own a car or a bike I'm forced to walk or take transit everywhere, so getting everying localy might be a little bit of a problem. I'm not say this challenge is wrong, I just wish it was more accessible to everyone.
The real issue here is why people (such as me) who can not afford fresh food are forced to eat food that is polluting their bodies. There is a simple solution; don't eat that. I have found that it costs just as much to by fresh food then to go out to a fast food restaurant for a meal every day. You don't need to go to Whole Foods and spend everything you earned on 5 gingergold apples flown in from the hills of West Virgina and a pound of 100% free trade-organic coffee from Peru. You just need to keep shopping where you shop, but look at where the food your eating is coming from and whats in it. You can buy organic/fresh/healthly at a local store, it just takes effort. There is no need to hop around the city going from specialty store to speciality store. The reason they charge such a high amount is because the people who can afford to spend their time hopping from store to store can afford to pay twice what I can.
And if all else fails, make it. You can make a lot of peanut butter if you put it together yourself.