@ddzx
(17,560tpa x $14,000/t) + (236,000tpa x $3000/t) + (637,000 x $300/t) divided by 0.75 = A$1.527B/year
Operating cost per tonne of ore = A$167 x 6Mtpa = A$1.002B/year
Therefore A$525M/year
The DFS refers to Annual Average Production which is where I'd say the difference comes from between the DFS stated cash flow (Pre-Tax) A$785M/year and the above calculated A$525M/year. Accounting for future higher prices etc..
