Ann: Blackstone Completes Ta Khoa Refinery Pre-feasibilty Study, page-98

Since this is a PFS, there will be a level on uncertainty and various assumptions used to derive in the PFS NPV number..
That is why current valuation would be a steep discount to the NPV of the project.
However, the NPV of the DBU provides an indication of what to expect.
Likewise, we know there would be another PFS for the upstream business unit..
As some of you guys assumed, say value of BSX be 10% of the NPV of $2B, that translate to $200m and this is before we look at the upstreaming mining activity, Hence, using the earlier scoping study NPV of $900m but lets assume final NPV for UBU be $750m and we take 10% of that NPV as current value of BSX upstream business.

So, assuming combined NPV of $2.75B of BSX, and using 10% value, current market cap of BSX should be $275m.

Current market cap of $146m represent another 85% upside potential to current sp.

DYOR..