The proof is the fact that Krn' feasibility study was conducted by the internationaly renowned firms

of Foster Wheeler and Ercosplan(potash solution mining experts. And apparently Wpx employed experts to conduct their feasibility study. 

So whose OPINION should we listen to? Mine or yours? Hardly. Seeing as we are not experts. I think we should trust the experts that went over every aspect  of the costs in detail and it obviously passed the stringent due dilligence of the independent experts the Indian firm who bought  20% of Krn employed.