At these levels i do not believe that GBG could afford to buy SDL they are waiting on feasibility of thier own ore body let alone try to takeover a $400m SDL.
If it was going to happened would have happened already.
Don't take this as a GBG downramp, I believe gbg will have no problem securing feasibility and has got a 300%+ SP gain over the next 18 months IMHO, but they do not have the $$$ to buy SDL out methinks
only my 2 cents
YRT