I agree, but we need to be careful. What is a "luxury"? What if the yacht is being used to ferry refugees? And would we tax the money that Elon Musk invested into Tesla or SpaceX during their early days? If we had, we would have killed those companies - but that investment was discretionary, and one could call that spending an "obscenity" because it was not going to feed the hungry.

So while I agree, and Betsy Devos's family's 10 super yachts come to mind, we need to be very careful about this, because while most rich people waste their money on themselves, there is a small percent who spend it in brilliant ways that government would never imagine to, and change the world by doing so.