We can have fun with this. Things change and nobody wants to go through pages and pages of posts for these opinions.
I say $5 USD.
There are a few things to look at. The NPV in the FS is the most significant as there is far more data behind that valuation than anything else. At $17B and roughly 200 million shares, let's say each share is worth $6.50, but each share clearly is not worth that today else the pps wouldn't be ~.53. It trades here because there is significant risk, mostly revolving around financing, but certainly around metal pricing, the actual scandium market and the accuracy of resource measurements as well.
One could also argue there is tremendous upside. There are potentially more resources than indicated in the report. As mentioned a few times today already, 32 years is likely a minimum to the life expectancy, but pulling in numbers greater than 32 years out has minimum effect on NPV and would not have been beneficial to the BFS. You also have potential government interest and niobium/scandium industry growth that provides upside.
I took the $6.50 of the NPV, assumed a company was looking for at least a 25% ROI in a buyout, and rounded down to $5.
This is all my unsubstantiated theory and should not be construed as investment advice.