Keurig single cup coffee has changed the game for coffee drinkers. There is now a plethora of coffee, tea, and cocoa blends that can be freshly brewed by the cup. However, these little conveniences will put a dent in your pocket before you know it. Instead of forking out the cash to save yourself half a second, invest in a reusable K-Cup filter from Amazon. Doing so could save you up to 50 cents per cup of coffee!