RE:RE:RE:Refractory gold not easy or cheap to get. See Barrick MRE I'll humor you with an answer this time....you don't stop drilling and doing a PEA when the grades are getting better. You'd only have to re-do it the next year.
Companies run drill programs to try and add to what they already know they have.
Also, most of those companies have been drilling for 12-30 years by the time they do a PEA. We've not even been drilling for 10 years yet.