I'm not sure what question you're asking. The PEA is a first pass economic analysis. It will review a range of mill sizes, production rates, capital costs ,operating costs, grade cut-offs and cash flow projections to determine an optimum balance based on the experience of the company doing the PEA. All it really does is determine if the project has a reasonable chance of making money using reasonable assumptions. Operating costs above $ 500/oz would be considered too high so that's probably why Brian threw that number out there. Furthermore you can't take the results of the PEA to the bank for financing, you need a feasibility study for that. There will be a need to raise money to get through the rest of this year and pay for the feasibility study but it had better be at a much higher share price than $ 0.345 .