I have a refillable adapter and normally just use that. I don't need a different flavor of coffee everyday and see no reason to pay about 5 times the cost just so I can avoid the hassle of putting one scoop of coffee in filter and snapping the lid on. It varies by brand but you typically end up paying $50-60 a pound for something you could by in bag for $12. Besides the plastic cup are terrible for the environment and every one you will use will hang around in a land fill for centuries.

Since my first cup is the one I take on the road with me I don't need to make full put if I did and poured the rest down the sink it would still be cheaper than using the plastic cups. The speed and one cup brewing are nice though.