The point is to have a program that the first 3D printers which will be generally available can use to produce firearms. Metal printers are much more expensive and use more expensive feed-stock.
Well of course. Pricing is listed by CM3. It's always good to have a cheep, fast method to prototype, then determine the best technology to produce a final product.
The nice thing about metal 3D printers is that there's very little pre-production setup like you have with a CNC or other fab tools. Everyone can have a custom product with each print and there is very little switch over costs (efficient run of 1). Read the FAQ / pricing model for the links I provided. There are no volume discounts.
Also, I imagine 3D coops and group investments will emerge and democratize ideas for physical goods. The cost curve will dip rapidly.