So here they are. The WAR BANDAGE coasters. There are... eleven. I know. I still have some fiber left, but it's a 2-ply version, rather than a single-ply (which these are), and I am not sure yet that I want it to to become coasters, or something else.

The Striped Seven were single-plied on the wheel, using the long strips of fiber from the entire hank, so you get the long repetitions of color. The yarn was thicker, too, and not as even as the kick-spindle (learning curve!), so there is more variation in texture, and a thicker coaster overall.
Felting was harder than it should've been. Hot water, agitation...I mean, when I am not trying to shrink something, it's easy. But when I set out to do it, somehow I end up having to do it twice. There is still more stitch definition than I expected, especially on the Striped Seven, but I think that is also a feature of using too-small needles in the coaster itself, and thus having a pretty dense fiber before attempting to felt. On the other hand--these suckers are heat-proof and they will soak up a small ocean.
I also understand why a coaster might be $20 now, if you did the work entirely by hand. I didn't prep the fiber, or dye it; all I did was spin and knit, and I am guessing each individual Striped Seven has about 45-60 minutes of work in it. The kick-spindle four have more than that, because kick-spindles are slower.