From someone who is reasonably adept with ceramics and just bought another 100 pounds of clay this morning (aka I know how much 50 pounds of clay weighs) because I'm making a six foot tall piece in an intermediate/advanced ceramics class that I'm taking for fun: 50 pounds of clay is actually a lot, and not everyone can make a pot that big. So if someone managed to make one 50 pound pot, it would still require quite a lot of work. Plus, there's the assumption that the majority of the people in the class are interested in learning, so they will be trying to make something good.