A repeat of Prime's post, plus:

The mining sector's doyen, the late Julian Baring used a simple valuation method of applying :
1% of the property?s contained base metal to arrive at an implied value. The study uses US $3.00/lb Cu and US $1300/oz Au

2.Julian Baring used the same valuation method for gold exploration properties. However, he advises a premium to base metal properties and suggests applying 10% of the property's contained gold metal to arrive at an implied value. The study uses US $1300/oz Au

It appears obvious to me that the high degree of competition between mining companies and their consideration of future prices (inflation, China, fear, culture etc) and Hog's examples of Andean & others all will play a role in their final estimate next summer. Also the mining - friendly democratic Peru, road access and availability of ore all add up to a very competitive bid after the drills heat up the property. Added heat that we will see will be the drill permit, drill plan, geophysical exploration of the new property, and the heat from my wife from the old song 'Gimmy some money too"