Like choosing between Ford and Holden, people have a preference when flying between Qantas and Virgin.
But not if you are a public servant on business, spending taxpayers' money.
There is a policy covering the 18 federal government departments and its many agencies of choosing "best fare of the day".
However, Centre Alliance senator Rex Patrick has questioned whether this is being followed.
Citing 2016/17 data, Senator Patrick put to Department of Finance officials during a Senate estimates hearing on Thursday that 534,000 Qantas flights were taken by public servants amounting $201 million compared to 233,000 Virgin flights worth just $61 million.
Using a crude calculation, the senator said this meant the average Qantas flight was $377 versus $261 for Virgin.
He found only one agency - the Australian Radiation Protection and Nuclear Safety Agency - had used more Virgin flights than Qantas.
"In general, my experience is that Virgin is normally a little cheaper," Senator Patrick said.
Finance department official Nicholas Hunt explained the "best fare of the day" doesn't necessarily mean cheapest because there are various operational requirements that need to be taken in account.
"It's not necessarily driven solely by the dollar although that is an important consideration," Mr Hunt told the hearing.
He also noted there were also a greater number of flights through Qantas to some regional locations.
However, he said the responsibility for implementing the policy is at the agency level, which surprised Senator Patrick given Finance had defined the policy.
Senator Patrick went on to question why Finance had spent $447,000 on Qantas flights while spending just $197,000 with Virgin.
Finance secretary Rosemary Huxtable was unable to confirm the senator's figures and took his questions on notice.
