I think we all agree that clearly WPL gets more appealing to BHP...

I think we all agree that clearly WPL gets more appealing to BHP the cheaper it gets. The point is that your Heading and related comment is provocative and not correct re: Charlie.
We have to agree to disagree but I also do not subscribe to your comment below that BHP would "not in a million years going to bid.... mid $40s" - (WPL hasnt really been below $40 in 2 years)it is a fact and publicly disclosed that they were looking at WPL seriously to the extent that they had sounded out WAs premier Colin Barnett. Additionally it would have been very easy for BHP to just say in response to ASX - we are not looking at WPL - they didnt and responded with legalese that did not deny they were in "discussions".
I dont expect BHP to move on WPL, they are the only large enough bidder who can get regulatory approval so no competition, they will hope that WPL management screw up again, general economic weakness before they moved - perhaps low to mid $30s as a starting point + premium to offset execution /political risks.
All the best