Interesting proposition, isn't it.
The gold bug in me says, "hell yeah, tax em, that only means my PM's will rise in value!"
but then the libertarian in me says "taxes are bad, mmkay."
Plus, something tells me this basically only means more FRNs conjured from thin air. Cant put it together, but taxes are not actual wealth creation, so all this would do is make more fake money, which in turn would cause PM's to rise even higher.