Cheap Airfares

[FlyingMummy]

I used to work in the aviation industry and can also back up that $229 SYD-PER is probably the best you will get. I'm no mathematician, but I daresay that driving to Perth will work out more expensive, when you factor in petrol, a car service, food, accommodation on the way (coz no way could anyone do that drivein one hit!) plus I'd also be taking out the top level of roadside assistance that money can buy.
Just for safety reasons I would be against a female and her daughter doing that drive alone. The only other thing that might be worth a try is getting a cheap flight to Adelaide and then getting a flight from Adelaide to Perth. (This would only work if you could get like a $30 flight to Adelaide.) Cheapest flights are usually on tuesdays. Best of luck. Or do you know anyone who is willing to give you some frequent flyer points?

[FlyingMummy]

...Or try for a cheap flight to Melbourne and then a flight to Perth, as Tiger flies to Perth out of Melbourne but not Adelaide. And I'm pretty sure their prices can only be found on the Tiger website
(I may be wrong.) Tiger would be the cheapest way to fly there as long as you're not fussy with dates....they are currently doing $150 fares to Perth from Melbourne for early August.