Ann: Appendix 3B, page-57

"That 8% discount rate doesn't come out of the cashflow and reduce the IRR in that BFS" - cannot see the relevance of this statement. I did not mention IRR in my post at all.
"It merely discounts the cashflow cumulatively each year to come up with the NPV figure" - Good because the NPV is specifically what I was interested in.
"An 8% loan repayment on 60% of the capex for a set loan period hasn't been physically modelled". I'm not getting too tied up with the percentage debt vs equity at this stage but 60% is probably around the mark. My point is that both equity and debt will want some enticement to invest. For debt it is the interest rate and for equity it is the discount rate. If those things are both the same (which is a reasonable guess at this stage), then the NPV can be compared to the current MC - since if it were possible to borrow 100%, the NPV would turn out to be very close to $700M. In fact debt would be slightly better as it would be paid off pre-tax.