Q3 2012 Teck numbers for copper:

Revenue: $2,247

Gross Profit before Depreciation & Amortization: $1,070

Implied: Cost of production: (2,247 - 1,070): $1,171

Cost as a % of revenue: 1171/2247 = 52%

If a lb of copper is $3.2, then cost is $1.66

1) you should be using gross profit before depreciation & amortization ($1,070 instead of $804) because D & A is typically not included as "operating cost"

2) Just express the cost as a % of revenue, and you can approximate the operating cost for copper production easily

3) CUU has a negative cost; so the gross profit would be whatever the price of copper plus the negative amount - that should make CUU very very attractive

JMO