POS WSA SIR compared

I'm getting ready to run for cover so fire at will...lol...but:
have done a quick exercise on valuation to try and make sense of the diverging market caps we have for WSA, SIR and POS:

WSA: costs to produce and sell a pound of Ni in 2014 calculated by deducting their operating cash flow from sales revenue is $4.07/lb. This excludes capex requirements and interest payments. WSA  is said to get about 70% of spot price so at current price of $7.84/lb that is $5.48 and WSA clears $1.41/lb.
They produced 25,700t of Ni in 2014 from a 4.8% Ni in ore grade - that's an exceptionally high grade explaining their margin.
MC = $1.03B

SIR: yet to start mining and producing but DFS says their AISC is $2.32/lb clearing them $3.16/lb. They plan to produce 26,000t of Ni per year. So their AISC says it all and explains the MC. Clearly SIR has still a risk premium in the MC and can probably go quite a bit higher.
MC = $1.286B

POS: yet to start producing. they have 156,000 tons of Ni from ore grade of 1.55% at Windarra, and 185,800 tons of Ni from ore grade 0.7% at Black Swan. We have yet to receive a JORC for Lake Johnston. So they have the processing capacity to match WSA and SIR yearly Ni production, but their ore grades on average are just above 1% roundabout. That means they have to process 75% more ore than WSA to produce the same amount of Ni. That could make their AISC quite a bit higher than WSA perhaps 50%? So +-$6/lb clearing them nothing and short by 52c/lb.
MC = $100m


So if WSAs margin of $1.41/lb gives them a MC of $1.03B then
for POS to lets say have a $300m MC it needs a Ni price of $9 and more of which they get 70% clearing 41c/lb -

Very rough calculation and does not take account of capex and interest payments i.e. financing structure - fire away .

Ni price needs to play ball and that is why imo Fredy (POS Mascot) is saying they are waiting for Ni price to rise.