I agree with Frank.FMG will be shipping over 100mtpa before GBG...

I agree with Frank.
FMG will be shipping over 100mtpa before GBG even start shipping Mag concentrate.
That means FMG will be probably earning over $1B p.a. while GBG may still be returning a negative EPS result.

Regarding valuation comparisons, it's a little early to say GBG is undervalued when they haven't got final approval for finance, nor even an approval to mine yet! It will happen, but it hasn't yet.
It has also being substantially diluted, so past price points aren't applicable if you are going by that.

What if CDB delay finance into next year, what of GBG's shareprice then as shareholders nervously await news?

We know GBG has great potential but it has lost the extra potential it once had for huge returns to shareholders with that part having been transferred to Ansteel in order to get the thing off the ground.

Which brings me to another point, no-one outside of GBG and Ansteel know the full particulars of the offtake agreements. Ansteel could possibly hold the power to run GBG into the ground by producing concentrate at a loss to feed their mills. GBG may not have a leg to stand on.

If you think that's impossible, who else except for myself suggested a share issue was a strong possibility in lieu of equity debt, or that Ansteel's underwriting wasn't worth the paper it was written on when GBG needed it?

Another reduction in IO prices could still follow next year, if China wins next year's argument, regardless. That could easily see the whole project postponed again.
"What's that you say, that won't happen again"?
Well... have you forgotten that China shut down virtually their whole production during the Olympics just so the pollution wouldn't appear as bad on TV to foreigners. Think they couldn't do similar to ensure a better bargaining position, well...
What about the single desk they are setting up in time for next year's bargaining?

So to say it's undervalued when they haven't even turned the first sod is still a bit presumptious.
And as someone said a while back, GBG has to eat whatever Ansteel decides to feed them- not the other way around.

In 2-3 years time we can all attempt a reasonable valuation of GBG, not just yet.
but not so easily just yet.