Well, if anyone would like to let us borrow a gear to make a mold, that would be great. (We being myself and my brother in engineering) We plan to make a mold, cast a gear, test it, cast a few more, and then make a multi gear mold out of more expensive material. This way, with the more expensive mold material, we can cast hundreds before the mold is used up. Of course the disclaimer is the same with anything in the manufacturing process. Things can go wrong, so its a risk to whoever donates the gear. I've seen machine heads dive into work pieces that cost thousands and thousands of dollars.
But, I don't see much trouble with molding a little gear.
Here is a pic of the gear all programmed for the CNC machine in our CAD/CAM. If I ever order some small carbide cutters, I'm going to try to cut one someday.