for the bears...

For the bears who keep worrying about short-term costs during ramp up, this is only one side of the equation and in a sense 'fixed' (I use this expression loosely), even IF they may be higher during early phases. The other side of the equation (and the most important side) is revenues, and the price at which they sell (unhedged) production is based entirely on supply and demand, and this dynamic is only going to see copper prices rise during Boseto's life, even if there is a dip or two along the way:

# Globally, due to mine closures, supply levels are expected to drop by 1.5 million tonnes between 2013-2016, and

# China & India demand are expected to increase to half of world copper demand by 2020 (from currently ~40%+); using current numbers this is an ADDITIONAL 2+ million tonnes per year.

There is only one direction for copper prices in the medium term, and in time this will feed through to the share price in an extraordinary way.