Don't forget wage and salary increase pressures over those years and pressure at every other single commodity economy wide even the milk and coffee all from nowhere but the tax.
BHP simply had no viable choice under this government, how in gods name can anyone under such tax's plan that far into the future....whats the bet, when the libs get in and right the wrongs and the SA government has evolved to a liberal leader the mine will 'somehow' to the left lol become viable again....to risk ignoring today's ideologically based sovereign risks is a massive risk.