"Edgy says the orebody is worth $650 per tonne."
CMP, That is from using Kitco metal value calculator.
Average Indicated: ~$750
Average inferred: ~$550
But these are metals in the ground.
For more realistic value, take off 20% because recovery is typically 80%.
About 90% for primary metal and it can drop to as low as 60% for third or fourth metal.
So recovered metal becomes $520, subtract operating cost of $120 you get a round number of $400 per ton as profit before taxes etc.
I like round numbers.