Justa, I reckon he has just pulled the number ($5.50) out of his backside. I have attached a short video released at the time the GSA was signed with Santos in which
Colby advises "...as per our pricingguidance...$6to$7..." per GJ (circa 50 sec in). Obviously an indicative price while observing commercial in confidence protocolsFurther, I believe it is standard practice for these deals to be negotiated in US dollars and, of course, we do not know precise details on agreed currency exchange rates, CPI adjustments and gas price movements etc.
Spoiler alert: Wot, don't watch to the end as your blood will boil when reference is made to debt/equity.