Vista - bewarePrevious operator was Pegasus Gold, and they went bankrupt in 1997 or thereabouts. When I first looked at Vista a few years ago, I got the impression from somewhere that the ore had high levels of contaminants. Subsequently, I ran across passing reference to the ore being ultra-hard.
Whatever the exact problem is, you would need to consult an industry insider. This is one of those situations where just looking at the numbers can lead you seriously astray.
Australia has a mining industry and talent every bit as good as our own. That Mt Todd has sat on the proverbial shelf for decades is all you need to know.