ADarwin: Road/train trip Darwin-Alice springs, Stuart highway
It is a very hot time of year so can I suggest taking the Ghan train to Alice Springs..the train stops for sightseeing at Katherine. You could then sit back in air conditioned comfort and enjoy the red vast outback. Lovely meals...
AAustralia: Cheapest way to go from Brisbane to Alice Springs? Railway? Car? Airplane?
I would fly Brisbane direct to Ayers Rock and spend a couple of days exploring the area and the beautiful sunset/sunrise. You could then get a coach to Alice Springs via Kings Canyon Resortand experience the vast outback en route....