This makes sense. Recently I learned that there's a collectors market for marbles. Like, people will pay thousands of dollars for a glass marble. Who knew? An article talked at length about the difficulties involved in making a really good marble. There's all sorts of tricky things to manage and a million ways to mess up. But that's part of the fun, right? A collector wouldn't spend thousands of dollars on a glass marble that's easy to make. And if marbles were easy to make, surely a talented craftsman wouldn't devote their life to making them.