That's a very good question. If you look at the metals' prices used to determine the cut off grade for the pit optimization you might end up with the same question about the pit, short of a return to sane precious metal prices. As I understand the present mine (potential) strategy the underground is basically a portal low in the pit to access the part of the resource too deep for the pit methods, so it is not exactly like there is a lot of ramping to depth through barren material to get to minable resource.
They are using for underground cut-off 125% of the cut-off for pit, which is a sizable estimate for the increased cost.
Personally I would like to see the numbers if everything was redone to use say a 3 month trailing average metals prices instead of what I assume is the more usual 3 year trailing average.
IMO with KTN the real story is the blue-sky potential, the hints of gold now, the diatreme extent in the land package, etc.. Is the sliver/lead/zinc representative of halo mineralization cover associated with primarily gold mineralization closer to source ? It is imo all pretty early stage on that front.
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