I found one in a collection a couple years ago. I don't know much about it, only that I did a bit of research, and found out there are a fair number around. They seem to be missing the lid a lot of the time. I have seen a few in the past couple years, and they always seen to be chipped up or cracked. Maybe its the type of porcelain that was used.
In good condition with a lid, they seem to be worth about 40-50 at shows.