Ok let me clarify as I see it. Management is not trying to raise $10-15m to present to large investors. That has not been the strategy. Management is trying to sell a 15% stake in LLC for about $50m. They believe the previous studies are still valid, in fact they believe the bottom line has improved some. So to anwswer your question, I would say the reason management have not raised $10-15m is because they haven't been trying to do this - it has not been neccessary.

Once they have raised the $50m equity and then RCA put in their $20m, LLC will have something close to $800m in equity (including the land).

This $800 is then used as collateral with lenders (debt) to raise the construction funding for Phase 1, which should be quite straighforward. Note that construction funding is expected to come from lenders as opposed to being raised from investors.

So management say they have 1 investor signed for what should be somewhere in the region of a $50m investment, and two which are close to committing. So why do more studies to attract investors??