Osisko - SkeenaTo figure the value of the Osisko deal, you should do a thought experiment. Namely, what did Goldfields own yesterday, (50% of Windfall but consider they hadn't yet paid 2nd tranche of $300 million) versus what do they own today (100% of Osisko).
Per the original deal, OSK and GFI were to share $250 million in pre-construction expense and $789 capex. Now that is all borne by GFI. So yes, the deal is worth somewhat more than headline $2.16 B but no, it's not double.
I would agree with lumpy that takeovers are completely unpredictable, but the Osisko deal really highlights what an industry player is willing to pay for a quality asset. If you only ascribe 50% value to Osisko's inferred resources, these 2 companies are very similar in terms of resources and time frame to production.