pre-feasibility study at $1650 oz

This is taken from their Pre-Feasibility Study released on the 12 October 2012:

"This scenario generates a Cumulative Revenue of US$2 Billion with Operating Costs of US$ 800 million generating a pre-tax internal rate of return of 28% and payback period of 4 years based on US$1650/oz gold price."

Gold price today is $1477 oz.

Question 1: What does this mean for IDC holders and the PFS?
Question 2: What price can IDC extract an OZ of gold?

Thanks in advance...