Author suggests that in assessing gold miner's potential for profit the price of gold is almost irrelevant and that the key measure is the difference between industrial commmodities and the price of gold.  For example gold mining in the 1930s was wildly profitable when the POG was $34.00 and the price of oil was 97 cents.

 

http://www.forbes.com/sites/realspin/2012/07/02/gold-mining-stocks-are-an-increasingly-attractive-opportunity/