I'll preface by saying I don't think your valuation is as unrealistic as $5+ given what we know about the current NPV's...however, 8% seems high after an EA and further infill drilling. You're also giving $0 for the rest of the lands...what's included in the FS and the rest of the lands are separate. Ya, it's just potential and it's not worth billions but it's not worth 0 either.
I'm also curious about the process you suggest. Do you really think that a few infill drills will make them go "let's manage our risk with 20%" to "we should buy the whole thing!"
You suggest they don't get anything if they spend $300M and need to spend $340M...but if the mine is going to be built, there's no reason to stop spending. If it isn't going to be built, then it doesn't matter if they own 0% or 20% or 75%...because it's not worth anything if you can't actually mine it. I just don't understand if a mine will be built, why they wouldn't want more for a miniscule amount. I understand not buying us out right away - but not your logic on the %.