Actually, Nevada gold averages about $200/oz, and when the price drops below the $275-300 range, they start shutting down mines. Still, Nevada has cheap ore and lots of it, which is why it is one of the leading gold producers in the world. Nevada's production reserves far outstrip their actual production, largely because the demand doesn't exist to support bringing more capacity on-line. There are a lot of relatively cheap deposits that haven't been tapped simply because doing so would only cannabalize the existing production sites. I own gold ore bodies in Nevada, and an extremely rich copper deposit as well, but there is simply too many good production sites sitting idle to waste my time and money capitalizing on them. The market has spoken. Incidentally, I think the gold standard is a useless idea as well; it doesn't fix the problem, just shifts it to a different place.
You neglect to mention what you see as the problem that is shifted rather than fixed by a gold standard?