LeDerp, might very much be the case that your numbers and...

LeDerp, might very much be the case that your numbers and methodoly don't add up.
The total cash cost to extract an ounce (oz.) of gold is calculated by deducting product sales revenues from total production costs.
LOM production costs are stated as 800,000,000.
LOM revenue (predicted) is 1,890,000,000.
LOM Net untaxed profit is 1,090,000,000.
1,090,000,000 divided by 1,000,000 = pre tax/royalty @ cash cost of $560 per oz.
Then +79.20 per oz royalty.
This brings us to 639.20 as a base cash cost pre tax.
Tax?
Who knows, probably non in the first 4 years and a lot of carry forward credits.
Why did you choose to add the cost of plant (which is Capex and in most case a hard physical asset) into the equation?
Capex on plant is not included in “production costs” for the purposes of determining the actual cost of extracting and producing an oz of gold.
I think, with the utmost respect, that your “discretionary” calculations are misleading.