If you want to pack it yourself, most bike shops would be happy to give you a bike box for free. If you want them to pack it, most should be willing to do it for $20-$30.
As for shipping, I've used Greyhound Freight before - $97 door to door, Syd-Melb (and vice versa). It may be more for longer distances, but I think it was a flat rate that they charged.