Webjet - This is the best place to look
Originally Posted by Days of Grace
How much is a ticket and which airline should we use?
It compares all the airlines on the days you want to fly and where you want to fly to. Jetstar or Virgin are the cheapest (they are no frills, but you will survive for a 90 minute flight from Sydney to Brisbane). I have flown Qantas between Sydney and Brisbane, but I didn't have to pay for the flight (it was already paid for me) but they are the more expensive option. Otherwise domestically I have flown Virgin Blue and they are fine and so is Jetstar. I flew with them from the Gold Coast to Osaka (direct) and it was fine, so there shouldn't be any problems flying between Sydney and Brisbane.
Or come to the Gold Coast instead of Brisbane.