A couple of us here in Brisbane have been looking for a personal ball spinner and would much rather buy one than try and build something. The pro shops don't appear too interested in selling one.
One problem you (Vertex) may face is the exchange rate. Currently your cheapest machine would retail at over A$300 (based on direct conversion from US$169) not including any shipping charges. That's probably a bit high even though some of us would love the ability to freshen up our equipment on a more regular basis.