The whole issue about the Cu price and the price to use is a...

The whole issue about the Cu price and the price to use is a key.
With the spot price of Cu where it is BHP's bluffing isn't going to get very far.

Just for clarification I believe the number of $3.60/lb used by Wood McKenzie (and conventionally) is arrived at as the price 90% of producers are at or below.
It certainly isn't the incentive price needed for others to come on stream to meet future demand they're calling AET-2.

I've heard Wood McKenzie talk on what they expect the future out look for Copper to be.
I was astounded that they think a very large part of future copper use is going to come from increased recycling. I suppose they also expect Al substitution.

My take is that well before the mine is built whether Cu is going to be $US4/lb or $6/lb will be determined. At present inflation (especially on input prices) favours the latter, a global recession may (short term) favour the former (but gold will react too).

My position is if BHP & NCM shake me out of SOLG at a lower CU price I switch those moneys to other would be Cu copper projects who are being impacted by the same forces. In DGR were being buffered by High Li prices too.

All IMVHO (and Bring it!)