Good question! Simply put....using just 50% of nav (which is quite low to use)

VD npv Canadian was 1 billion

SC npv unknown currently 

Lets assume around 4 billion Canadian (25% interest gives us 1 billion Canadian)

Also will the buyout be based on post tax metrics or pre tax metrics? Let's say post tax for safety net.

vd npv is 800 million CAD post tax 

So minimum 400 million deal at 50% nav!

sc around 500 million deal at 50% nav!

both assets give you nearly 1 billion deal. This is only at 50% nav. Not factoring exploration potential and JV contract terms.

I figure copper fox looking closer to 75-100% of nav!!! There's your higher buyout valuation.