The difference is that Healthscope had several parties eyeing off the company (I held those shares). They had to outdo each other in bids. If you have more parties in the mix for CST, you'll get higher bids. Not sure though, if the CST action group will sell for <$10, and that's the bind.
Maybe someone should ask them what they'll accept, and that could be a negotiating point? It just seems a bit fuzzy when all the group will say is that the company is worth $10 when the shares were trading at $3 (and will do so again, imo, if the takeover fails).
CST Price at posting:
$3.19 Sentiment: None Disclosure: Not Held