Dontcryforme,
Yes GOG also has some high grade veins. In the old ECU resource report they had cutoff values of $35/tonne for bulk mining and $50/tonne for narrow veins. I would guess now those costs are close to double that. So for bulk mining the grade needs to be about 70% as high as the vein mining. The reported 4 oz total grades are not anywhere near 70% of the Golden vein ore values. I have read mining articals in the past that say there is no such thing as an open pit silver mine that is profitable.