We can all play with numbers as long as we like. One can just about prove black is white if you keep doing it long enough.
My attempt...
To carry 2 hours extra fuel would cost closer to 230kg of fuel rather than 40kg.
So how about one hour or thereabouts? Around $150-200 per flight, divided by say 140 pax, mmmm, should we ask the pax if they want to pay one dollar more? They already believe that "the system" is safe and that is what CASA does for them for their tax dollars.
When you start talking $7 million dollars a year it sounds very impressive, but divide that into the passengers carried per year. Then what do you get.
Ultimately these things will happen occasionally. That is why the person in seat 0A gets to make the FINAL decision.
What about this...a 737 lands at ADL in fine weather that morning and the nose gear collapses, aircraft comes to rest on the intersection of both runways. No BOM to blame this time. Make a command decision. For the poster who said that we rely on BOM every time we flight plan all I can say is, not without considering the above scenario EVERY TIME I take a jet into the air.