Anyone familiar with the economics of a single serving coffee pot vs. a conventional one?

I want to compare the price of coffee used in a Keurig single cup coffee maker to the price of coffee used in a conventional coffee pot (Just the prices of the coffee, not the makers). Has any jelly switched over to a Keurig coffee maker? Was it more or less expensive to drink the same amount of cups of coffee with the two different types of coffee (K-cups vs. Folgers for example)? Or do you know of any sites that have figured out the comparisons of cost?