Your numbers are half way there Webgogs. You just need to factor in what the mine is worth today. The bottom of SC won't be seen for more than 25 years. Calculate the yearly income in metals, subtract the mining costs and discount each year for 25 years.

Say, using if we use your metal prices, RE metal recoveries and metal selling costs etc, we are left with a Net Revenue is $550M a year for each full year you mine (360 days a year).

Discounting the sum $550M over 25 years at 8% leaves you $80M for that final year. In other terms. A person using NPV will say that that $550M income in year 25 is only worth $80M to me know if i were to buy it.

Starter Pit and Capex can make a signficant difference

Using $550M Net revenue for each year.... And $3B even spent over 4 yrs prior to mining....

Yr Net Revenue (NPV)

-4 -$300,000,000

-3 -$600,000,000

-2 -$900,000,000

-1 -$1,200,000,000 (Total of $3B)

1 $509,411,462 (I discount this year when it probably should be Zero => add $50m)

2 $471,677,279

3 $436,738,222

4 $404,387,242

5 $374,432,632

6 $346,696,881

7 $321,015,631

8 $297,236,695

9 $275,219,162

10 $254,832,558

11 $235,956,072

12 $218,477,844

13 $202,294,300

14 $187,309,537

15 $173,434,757

16 $160,587,738

17 $148,692,350

18 $137,678,102

19 $127,479,724

20 $118,036,781

21 $109,293,316

22 $101,197,515

25 $80,333,850

24 $35,571,829 (partial year)

Total NPV $2,727,991,477

http://en.wikipedia.org/wiki/Net_present_value