228 made about 24
GUS balls (our replication orbit balls).
It took several students and mentors an entire weekend to do so. Our final material costs were in the $8-$9 range per ball.
It may sound like a good idea at first to make lots of them to sell, but by the time about 18 of them were made we were starting to go crazy. It's very repetitious.
So before you go on any further, I'd make like a half dozen of them first just for your team. Then ask yourself if you really want to make more of them to sell, because I can guarantee you most people's patience for making these balls will falter after about 20 or 30 of them.