appropriateness of metal equivs

I would be interested to read peoples views on the metal equiv's

here's my initial two bob's worth:

Cobalt is roughly 50% of the metal in the measured/indicated resource.
Cobalt is currently $10/lb on the LME for a 3mnth seller
CDU use $56/lb in the CuEquiv. calculation.

Some posters claim the difference is due to sulphur credits

A report freely available on the web on the Mt Isa smelter
(google suphur credit from smelter)
states that MIM averaged over ten years of 255Kt Cu/year produced
they got 160Kt/year of SO2 from this 255Kt each year on average.
H2SO4 is worth about $100/tonne.
There is 1 S in each compound so they are 1:1 in terms of sulpur.

CDU have around 283 Kt of CuEquiv from the 30Mt resource.
So on back of envelope (based on MIM data) the smelter of their con
could get around 160Kt odd Sulphur from the 30Mt.
At $100/tonne, this would be about $16M worth.
at that price, the value per tonne of sulphur from the whole 30Mt resource
would be 0.53c/tonne of ore.
this doesn't count any fee the smelter may have to pass on.

Cobalt is around 1lb to the tonne of ore (472ppm) over the 30Mt
todays LME 3mnth rate/lb equates to about $10 per tonne of ore.
cdu use $56/lb which is likewise then roughly $56/tonne of ore

so with a theoretical $46/tonne shortfall to satisfy the cdu Equiv,
only about 0.53c/tonne of that can be expected from any sulphur product
if the MIM data is accurate (and I havent mis-calculated).

so is the cobalt worth $300M or $2B ?
That is the sort of range the difference from my rough calc's

given cobalt makes up roughly half of the metal in the 30Mt
this is quite a stretch of the imagination, imo.
borderline irresponsible, is my honest view.