I shipped my computer from Hobart to Melbourne, insured, not overnight - weighed 12.5 kg (without packaging) and cost $39.00. This in comparison to Pack & Send, who quoted me $145 for shipping alone.

Fastway don't provide any packing service, so if you're not able to package something yourself, you may have to take it elsewhere for packing before you ship it (this would have been my course of action had I chosen to have it professionally packed). They do provide a tracking number, so you can track it online. I've found this a useful tool as a recipient, not just a sender.
My computer shipped today - I guess if it doesn't arrive, or arrives damaged, I may be back to update this entry!

Approximate cost: $39.00