Expert Valuation for EGM, page-7

The sensitivity Tornado relates to the discounted cash flow variation as it changes with the changed parameter. So a 10% increase in copper price has to include a deduction for higher royalties, and any other factor linked to price, and it has then got be discounted back at 9.6%pa to today. I hope that helps.
Since directors and management bought a substantial number of shares at an effective price of 8.3 cents I think the share price will be higher once results are published. In the short term they are as confused (and probably as disappointed) as other shareholders.