Veryhairy: I am restating what Jason Brewer has said.
Consider this scenario as stated by Jason Brewer:
250k tonnes per year production with a:
$50 profit per tonne = $12.5 milllion profit
$100 profit per tonne = $25 million profit
$150 profit per tonne = $37.5 million profit
$200 profit per tonne - $50 million profit