My pillow is small size, filled with Buckwheat grains. It was on sale about 75 percent OFF, at Filene's Basement, a well-known discount store in Washington, DC.
Never get the buckwheat wet--not even damp. Double-case it at all times, with a heavy muslin inner case, to prevent sweat, oily hair, perfume, spilled foods... or any other hair product from messing up the actual pillow.
It is wonderful, especially a benefit to anyone who tosses and turns, sleeps light, and must re-adjust all through the night, has neck pains, etc. I don't think I could live without it, I travel with it. ---Oh, and did I mention I've been using it for almost 23 years?