Done some quick math, based on last available qtrly report: https://hotcopper.com.au/threads/ann-quarterly-activities-report.4873057/
Used the current spot rate as per for SC6.0:
And the FY23 sales price from PLS for the tantalite:
Which brings us to the figures:
Only thing I think I've been lenient on is the opex - which has probably increased since 2019 (the opex i've used is 2019 figures)...
In any case - paying $180mil for something that is generating apx $80 mil per quarter is a pretty phenomenal deal for Mr Ellison.
