I have just done a quick search of the annual reports looking...

I have just done a quick search of the annual reports looking for cut-off grades

for Reward the cut-off grade is said to be 5 g/t and since that's what the geos regard as break-even it converts to A$190 cash costs per tonne of ore, that number is typical of the underground miners in the Lachlan fold belt

for Red Hill the cut-off grade is said to be 1 g/t and since that's what the geos regard as break-even for that style of deposit - it converts to about A$40 cash costs per tonne of ore, that number is typical of an open cut mining operation in West Aust

actually the approx average cash costs per tonne for WA open-cut ore is about A$30 per tonne

incidentally, MCO have stated in previous announcements that their cash costs per tonne will be about A$250

a few obvious conclusions:

A$200 cash costs per tonne is a great "ball park" number to use for all underground mining operations

if Red Hill becomes an underground operation the cut-off grade will approach 5 g/t

analysis on the basis of cash costs per tonne is much more sensible than looking at cash costs per ounce because cash costs per tonne is a stable number and relatively predictable - when highly variable head grades are introduced into the calculations then profitability becomes very confusing