If you're clever and keep it under the 150 AUD mark then you will most probably get away with it.
The "risk" is in using their express carrier, (TNT I think) they will most probably end up charging you the VAT and duty (8%).
Most of us use the "free" shipping option for over 80 AUD (easily spent lol) and wait for the 2-3 weeks the Aussie post takes to get here, MUCH safer ;)
Timberbits are great to deal with, very responsive via email, and if there's ever anything wrong, they put it right pdq in my experience.
Get shopping !