McDonalds is definitely cheaper per Calorie.
(I think!)
Hell, Tacobell has a 550 calories per dollar in their beef burrito. (IIRC).
That would be like 10 oz of chicken.
which is pretty calorie dense for a home processed food. Or about 7 apples, which still costs more.
SO, depends on how you determine costs. If you count everything as calories in and calories out, and want to see the costs per calorie, a lot of fast food / canned and processed food, is a much better deal for caloric volume.
If you put in the cost of personal labor, it is _FAR_ cheaper.
Imagine you were, yourself, a food industry worker making 7.50 an hour. You just got your food from your local CSA farm share, and you cooked up (time to cook 1.5 hours), you just spent 11.25 dollars of your life cooking for food that in itself was more expensive.
I spent 1 hour last night with my GF making food, we make far far more than minimum wage, and it took 2 people. So lets pretend our time is worth a dollar a minute (combined, it is worth more but this an example), that would be 60 bucks of "effort" put in.
Etc.... etc... Even if you just take our income and divide by 3 (assuming we work 8 hours a day, but spread it out over 24 hours so that even sleeping itself would "cost" money) it would still imply 20 dollars an hour to make that food.
Far more than driving through McDonalds parking lot or Taco bell and getting the same calories that way.
It all depends on how you look at this stuff.
Take a look at this:
http://www.npr.org/templates/story/story.php?storyId=5360768
Where a guy determines the true cost of a tomato he gardened to be 64 dollars a tomato.
Very Very expensive.