2 to 2 1/2 hour flight time.

Qantas - you don't have to pay extra for luggage being checked in, you get food.
Virgin - you pay extra to have checked-in luggage, no food
Jetstar - you pay extra to have checked-in luggage, no food (unless you're lucky enough to be on a Qantas flight).

I'd look at webjet for flight times, for comparison between airlines, but book with individual airline websites. There was a $40 difference between the cost of a Qantas flight on webjet to the same flight on the Qantas website (cheaper on the Qantas site).