If you are a puzzle designer I have a question for you: of the following ways to sell your puzzles, which one do you prefer?
1. Direct sale (not auction)
4. Mass production.
Well as a designer with the goal of enjoying this as a hobby, I'm not really in this to make money. Though I'd certainly like to at least break even. I'd have to say my preferred method would be mass production. It would get my creation into the most hands for the most affordable price. That said its the method I have the least control over as I have yet to have any on my puzzles mass produced. Though I'm certainly open to being approached by any producer interested in my puzzles. To me, eBay has a place. I consider it a good way to sell the first signed prototypes of my puzzles and I've done that with a few though not all of my puzzles. I don't personally feel its the only way puzzles should be offered. Without someone stepping in and offering to mass produce my designs I feel Shapeways and Direct sale are the best way to go. For puzzles made from STL files Shapeways offers a great way to offer your designs to the public with minimal effort to you. For those that want finished and already stickered puzzles or puzzles not made from STL files, I think opening your puzzle up to direct sale gives you the means to offer your puzzle to the most that are interested in it as possible.
Just my 2 cents. I think you will see a wide range of preferences here. It will be about as wide as the reasons why designers started designing puzzles in the first place and what their personal goals are.