Two of the variables in cost per pound of Cu produced , would be...

Two of the variables in cost per pound of Cu produced , would be the grade they are mining at and the strip ratio to get the ore out , would think that would have more bearing on cost than changes in labour cost and power over the last year , I do notice the grade has fallen in the last 3 months .

I just use a rule of thumb (which may be wrong) that around 85% of the energy cost in a grinding ore down to around 125 microns from 25mm in size goes to the ball or SAG mill in a standard mining operation , and about 15% of energy is for crushing , in this operation they would not be using a ball mill .
Intuitively the energy used to crushing the oxide ore would be less than the fresh ore .

TO make the cathode from pregnant solution from the heaps I do not know how much energy is used just guessing it is not that much ?

Guess if you had the time you could go through their notes over the last year to get a better understanding of costs.