Adelaide - Brisbane is quite a long way. I usually pay $550 for Melbourne - Brisbane, and just paid $350 for Port Macquarie - Brisbane. By contrast, Gold Coast to close to Brisbane is $125 (and up to $200) so when you look at it per km, it is not so bad. Combine the airfare with the petrol cost, and a hotel/motel for one night, and it would not be too much different if you drove yourself, and you lose 2 days - assuming nothing goes wrong en-route, but if you need to stay another day somewhere, plus a tow truck/mechanic if something does go wrong, you can see that it just might be worth it to have someone do it. You don't say what the car is, but for a $466 car, I wouldn't like to chance it being a trouble free drive of 2700 km or so.
Send me a PM if you want the contact details. Not sure if he does this route, but I'm sure he will know someone who does.