The historical mine data in the GB area had average grades ranging from 4.1 to 31.6 g/t with an overall average grade of 12.7 g/t. Most of those mines operated pre 1950 so , while they had lower operating costs, the price of gold was much lower than today. A recent resource estimate in this area from Ontex used cut-off grades of 2.0 and 3.4 g/t with a cut grade cap of 40 g/t. These numbers were cranked out by a third party consulting firm, not Ontex. The actual values that should be used will depend obviously on the expected price of gold during production. The Ontex numbers projected an average gold price of $ 850 USD/oz, which is quite reasonable given the current state of the world economy.