You forgot a couple of important points in your calculation, which are hard to measure but valuable. What about the fact that it has potential to be mined for 50 to 100 years in a politically stable, mining friendly country who will enjoy wealth and prosperity from resources for decades to come? What about the rarity of such big PROFITABLE deposits with so much potential they would need to drill until we are all six feet under? What about the fact that just a few companies get to achieve these milestones (PEA to BFS) with available financing without being taken over with a lowball offer or shut down for any other reasons like poor management etc.
All this is probably along worth your low ball estimate of 2$ and change.
And then as you wrote, at one point insiders and Stilfel Nicholas paid over 2$ to acquire more share on top of their millions already purchased for pennies. Why would they do this? To average down?