When to buy Bandos Godsword?

I need to make some profit, and someone told me that Bandos Godsword is falling rapidly right now, and will soon skyrocket due to the wilderness update possibly.

http://services.runescape.com/m=itemdb_rs/Bandos_godsword/viewitem.ws?obj=11696&scale=2

When would be a good time to buy a few of them for maximum profit?

 

Sold mine for mid, go +150,000gp above.

 

I can buy one for minimum if I want. I'm asking when I should buy one, so that I can re-sell it when it gets higher...

 

BGS is hardly a major pking weapon. I'd say buy it when/if it hits 10-11M.

 

Thanks.

I think it's actually flipping now, it's up 100k today. But I don't want to risk it. I lost 2m yesterday from a failed flip attempt. :/ I just can't do it.