You talkin' to me?Have you explored these?
https://www.amazon.com/Resuable-Reu...19004&sr=8-1-spons&keywords=keurig+k400&psc=1
You can pick them up at a Bed Bath and Beyond also. I use mine with my home roasts in the morning for the quick cup or two before leaving for work.
I've got 3 or 4 of those refillable things. But the problem is...I'm lazy. And apparently so is everyone else that drinks coffee. I don't like to scoop coffee in them, then run it, then dump it, then clean it, then finally get my coffee, then repeat this for...like 4 more cups. Autodrip 12cup for the win in my house.