Keurig K-cup Magic:
Regardless of where you buy them, or what size box you buy, the k-cups all start the same. They are manufactured at the coffee roaster on assembly lines then packages for the different sales channel.
The question is really your goal. A primary advantage of the Keurig Brewing system and k-cups are the wide variety of coffees and teas that are available. And because of the different roasters, the different roast profiles that are available. There are over 170 varieties of coffee and teas available for the brewers from five unique roasters.
The difference in k-cups is the retailer. At retail, the difference is really price, slection and value. Each channel has its own advantages and disadvantages.
The chart below shows the basic differences between the k-cup sales channels. While each of the retailer will have sales (coffee clubs, 20% coupons, in store specials, internet retailers like
OneGreatCup seem to have the best overall mix of Selection, Value and Service.