Estimated maiden JORC at Aura Tank, page-9

Mining, transport and toll treatment at the Challenger mill will cost us around 1g/t. So if we go this route good profits can be made from Aurora Tank ore if the head grade is 2 g/t or more. Once we get to sulphide ore I think it is possible/likely that this option will be required. I am expecting grades above 3 g/t so this should be quite profitable (6g/t +/- 2g/t my rough estimate). The oxide zone at Aurora Tank is heap leachable so it could be a few years before this option is required.

Golf Bore can also produce 3 g/t head grade but the drilled zone should be heap leachable.

I don't know the costs of current heap leach operations but it would not be hard to google or ask a metallurgist. Certainly all up costs would be considerably less than the 1 g/t I quoted for toll treatment at Challenger.