Glad to hear that you found it interesting, @wizened!
And yes, it is discouraging that the piastre is heavily counterfeited. One has to be diligent when considering a purchase and choose vendor with care. But I don't think it sticks out compared to the
US Trade dollar, British
Trade dollar, Dragon Dollar, or others. They too are popular targets for forgeries directed to coin collectors. When it comes to counterfeits meant for circulation, it is a function of silver prices and which coins are circulating. I am not familiar with other examples, although I am sure there are more examples than the piastre and Australian florin.