The 16-cent lunch.
Not possible? Let's explore.
Back in college, I ate quite a number of Ramen noodles. When we went broke and had to slash even the food budget to the bare minimum, I took a package of these to work. Their cost. You guessed it: 16 cents.
If I ate these five-days a week for fifty-two weeks, my lunches would only total a mere $41.60.
For an added feature, brown up a package of hamburger and throw in a handful with the noodles. At least you'll get a bit of protein while you're at it.