RE:Valuation rangeExcellent analysis. Thank you for sharing.
Some points that might be worth considering:
1. If the construction phase last two years, isn't it unlikely that all cap ex cost will be incurred in the first year? Maybe 60-70% will be incurred in the first year and the remainder in the second?
2. Are you including depletion expense (exploration and extraction costs amortized on a pro rata basis with the consumption (production) of the overall mineral resource? It works similarly to depreciation in helping to shield the project from taxes. I'm not sure how much of the on-site production costs or how much of the upfront cap ex should flow into depletion.
3. By the middle of this year, trailing 2 year copper prices will approach $4 per pound.
4. Are you including off-site costs (e.g. smelter costs)? You'll see some very conservative estimates of this per pound from the 2011 John Thornton Santo Tomas Technical Report which you can Google. Off-site costs could be as low as $0.35 per pound, I believe.
5. Does your tax rate need to bump up by 10 percentage points to 48% to include employee profit sharing taxes? It isn't applicable to miners in the exploration & development phase, but I believe it does apply to miners in the production phase.
https://napsintl.com/mexico-manufacturing-news/important-information-about-profit-sharing-in-mexico/