RE: Combined Pb/Zn price....The beauty of DMS rejecting so much gangue before it hits the mill is that the size of the mill can be much smaller, significantly lowering capex and opex.
I "think" the mill was sized for ~1250 tpd (but my memory is fuzzy and I can't find any of my notes, so don't quote me on that).
When they start mining the open pitable deposits, it's very likely they will expand the mill. Lots of the low grade, big tonnage deposits are economic using DMS scalping off so much gangue (~2/3rds). If they double mill to ~2500 tpd, they would be mining ~7500 tpd at the open pit, which is easily done with a modest sized fleet. Cominco mined them at 11,000 tpd, but ran all of that thru a mill as they didn't have the benefit of DMS in those days. If they did, Pine Point would never have shut down.
I think the market will be stunned at how long TAM ends up mining at Pine Point. Most don't have a friggin clue how positively DMS affects the economics of the lower grade high tonnage open pits.