I still figure we've got to give well supported NPV numbers (and IRR), as that's what's been stated by management and expected by Teck and the industry. The real picture however that is decades ahead? Very hard to measure accurately as the sensitivity analyses are vastly affected by 10% differences either way. No offense to any of the engineers out there, but I'm amazed how few minings projects get the capex right (and if it isn't engineering's fault, then how bungled the procurement and construction go that send most projects well over budget). Very hard to predict where precisely metal prices will be also. If copper was still at $4.50 there'd be all sorts of crazy growth in mining right now and projects scrambling to get going. With the increasing uses of silver for new nanotechnologies and medicine, plus declining deposit grades, good days lay ahead.
At the end of the day, it's the value Teck and/or others put on our project. Teck needs to protect itself by leaving room for the downturns in the pricing cycles, yet Don Lindsay and company seem very bullish on near to medium term prices (next 3-4 years and beyond). A quick payback will be very enticing to Teck and its partners.