In addition to low cost of production it is fair to say that there is no point buying into a low cost producer if it is fully reflected in the share price.
You also need to hunt out the ones that are unloved/ undiscovered.
Two possibilities:
(1) EVG - Production <12 mths, lowest cost quartile, market cap $25m, NPV of their first project USD$78m (484k oz) + second, Ecuadorian project (MAYBE >1m oz).
(2) DRA - 75k oz pa production, ramping up to 100k. 1.18m oz resources (inc 20% interest in CHN project), costs about $600 per oz, margins improving as based in Finland and Sweden, thus costs in Euro.