Ann: Hydrocarbon Samples from Mukuyu-2 Discovery at Laboratory, page-412

I think there is an error in your calculations. Mscf or mcf means a thousand cubic feet not a million. So scaling up to 10 bcf per TCF means it's worth a lot more. According to your price estimate, 10 bcf should be worth 25 billion dollars (and incredible $A 12.50 per share based on 2 Bn shares for each Tcf).

The price estimate I found was different from yours - USD 375/mcf has recently increased to USD 800/mcf. Converting to AUD is about 1200/mcf so that would mean each 1% per TCF is worth about AUD 6 per share and therefore 0.1% helium per Tcf is worth about 60c. Please correct me if I'm wrong.