I cannot imagine one company that did an NPV 10 -12 years ago ( even 6 years) that calculated current/ recent prices for their minerals. Any company that did an NPV 10 years ago and perhaps calculated it would take 10 years to get an ROE / breakeven would be WAY WAY in front. They would be doing high 5's in the boardroom.
Commodity prices in the last 6 years have provided a massive boom to their economics and NPV calculations, including massive interest savings from increased cashflow.
They are way way in front of any NPV calculation but best to keep that quiet from the public so they can legitimise their complaints about this tax.
