Cubist is paying $13.50 per share for TSRX (forget about the other $2 which is based on future events that may not occur) or a total of about $646.2 million. However, since TSRX has $84 million in cash on its balance sheet with no debt, Cubist can use that money to offset its transaction cost, bringing its acquisition cost down to $562.2 million. This would suggest that they should pay a higher premium to stockholders than $13.50. Let me know if you think otherwise.
I think the point I'm trying to make is that the $84 million equates to $1.75 per share. If you add the $1.75 in cash per share to the $13.50, it equals $15.25, or nearly the amount of the buyout price plus the $2 CVR ($15.50).