What's a Nickel mine worth? Current valuation of market cap +...

What's a Nickel mine worth? Current valuation of market cap + debt has Santa Rita valued at 280m + 400 = 680m

BHP sold the Ravensthorpe Nickel mine to First Quantum in 2009 for 340m USD. It cost BHP 2.2b AUD to build

First Quantum expects an annual production of 39,000 tonnes of nickel for the first five years of production and an average of 28,000 tonnes per year for the mine's projected lifetime of 32 years

Cash costs at Ravensthorpe are 7usd / pound (long term forecast down to 5.25)

MBN expect 20,000 - 22,000 tonnes.
MBN Cash costs 7 usd/pound, longer forecast 6/pound.

Hypotheticaly a 500m price tag for Santa Rita translates to less than 25c / share.