also Robert the gold price was around AUS$900 when that 8gpt was used.
which gives about $220 per tonne cost, so the margin at 16pt is 600 less 225 = $375 per tonne and at 12gpt $225 per tonne margin
and of course at 20gpt its $550 using AUS1200 gold
or about $12million pa cash flow with no CAPEX