The Game Crafter is a print-on-demand board game making service, which I have used to make prototypes of some of my board games.
They have expanded their services since I first used them a few years ago to make a custom card game. Now they include custom boxes, quad-fold boards, game tiles, as well as wooden and plastic parts, and different sizes of cards.
Their interface is easy to use, and the help provides you with good information, and good templates you need to design the different elements of your game.
The quality of their components is good. Nice color, durable pieces, precise manufacturing.
If you are designing a game on the simpler side, The Game Crafter is a good way to go for the prototype, and for possibly selling some copies online. The card game I designed with them costs me $13 to get a copy of.
I calculated the cost of the current game I am making, and it would cost me $88 to make a copy from The Game Crafter. Even with the bulk discounting, it is not price efficient for selling copies. I probably won't even finish a complete prototype of that game there, and instead stick with the service to make simpler games.
If your game is more complicated, along the euro-game style, the costs can be too high to sell effectively online, but I still think it is a valuable service for making a nice looking prototype or two to send to publishers, or to give to a friend, especially for simpler games.