It's very true that as grades decline increased tonnage is required to maintain production levels ergo increasing costs of production and lowering/slowing overall profitability growth. I might also point out that when miners try to high grade existing mines they often screw-up the deposits long term life span and those ounces left behind are often lost to future development, this is why the best miners try to engineer lower grade mining sections when prices are higher which also leads to leveling of profit but not effecting life span of the mine, this creates a long term smoothing effect to revenue. It's a tough business requiring much more planning than many really understand and of course the wild fluctuations in gold/silver pricing adds some challenging issues as paper seems to control physical more than ever at the moment and geopolitical risks are elevated as demonstrated by recent Kinross & Barrick developments.

The bottom line is most of this stuff is priced into the stocks already demonstrated by the significant lows of most precious metal equities, somehow the market always seems to know and we never seem to learn this until near the bottom or after the fact. The good thing is that most of this stuff by being factored in to precious metal equites can only lead to higher valuations as the pendulum swings back to excess in the other direction. Having gotten hurt on the way down I intend to be there on the way back up.