Just ran across this. Plenty simple to make a drill powered lathe, then make all the wooden balls you want/need. Neat. I haven't priced wooden balls in awhile, but suspect it would mean a good saving when you make your own.
https://www.youtube-nocookie.com/embed/PtIjFg_XarU
https://www.youtube-nocookie.com/embed/PtIjFg_XarU