Using the above pay scales and PGK/AUD conversion rate.
Dash Classic skipper on PGK 271, 739 / $AUD 108452 pa.
After paying PNG tax that equals $AUD 5628.00 a month.
With the lower tax in AUS combined with 9.5% Super one only needs to earn $AUD80,000 pa living and working in Aus to be paid a total package of $AUD5733.00 per month (that includes the super received and the medicare levy paid).
B767 Skipper on PGK 428,062 / $ AUD 171,225
After paying PNG tax that equals $AUD 8661.00 a month.
As above criteria you would only need to earn $AUD 130,000 in Aus to take home a $AUD 8,700 per month package (super received and medicare levy paid).
Not the most competitive I ever seen, especially for a job where you have to live in POM.