We also quickly discovered that a lot of R2D2:s parts are not easy to come by. This is because they are either made in aluminium for R2D2 builders, or they are cast in resin, or 3d printed.
Getting the parts from Ebay would be extremly costly, as browsing the internet showed us. Aluminium parts are still the most expensive, but also the molded resin parts are quite expensive as they are made by hand, one at a time and R2D2 has alot of parts that you can't make by yourself.
So early in the process we looked at 3D printing as an option, to be able to do some of the parts at home. There is a nice community that shares 3D print files and if you have the access to a 3D printer you will be able to make these parts by yourself.
Flashforge Finder (SE) is a nice alternative for home printing, not a heated printbed though and only 14x14x14 building area posts some challenges.
Lucas Arts has the copyright of the R2D2 creation, but since the R2 builders club, doesnt sell these droids for money, and use them for charity. It has not been a problem within the community to build your own droid! At https://www.thingiverse.com/ you can find some parts, as an example. Within the community you could probably find more...
We also have taken contact to our local MakerSpace Luleå, and they also have a couple of Ultimakers 3D printing machines at their facilities, so we can also use them for some of our bigger prints.
3D print of R2D2 radar eye, turned out very nicely!