The BB-8 Builders group, an off-shoot of the R2 Builders group (of which Bazzack and I are both longstanding members, and through which we got lots of great info and support in building our respective astromechs), has released for non-commercial use, all of the STL files to print the BB-8 dome, dome details, and body details. It's therefore "just" a matter of getting access to a 3D printer of adequate specs. Using local 3D printer service providers, or contracting other US prop-makers, would come in at something like $720 for the 60-ish hours of printing time required, so it would be great (and should be feasible) to find a cheaper solution.
A local plastic shop, Cambrian Plastics, manufactures the correct size (500mm diam) acrylic spheres for the body, at a shade over $60 per hemisphere. http://cambrianplastics.co.nz/product/domes/
![Image](https://farm8.staticflickr.com/7723/17393952672_0e6b5800f5_c.jpg)