The $1000 value is product ONLY not including the shipping....
BUT if you go over the 1k, you are taxed on the shipping cost AS WELL....
as mentioned already, you will be contacted by customs hen it arrives in Australia if the declared value is over the limit, and you pay them directly. (that is if it is shipped regular mail)
IF it is shipped by a courier, ( anything other than UPS, USPS or Australia post) as regular mail/parcel then it is taxed NO MATTER the value...
Graham is also correct, it can be pre payed as well to speed things up.
Personally, I have never had any trouble and import products from the US weekly.
I just ensure each order is under the declared limit,
You could always ask the seller to split the case and send in two lots so each is below the value, (you ill need to trust them they wont search the boxes i guess) This way it may cost more in postage costs but in the long run be LESS that having to pay taxes.
The other option is to under declare... ( THIS IS ILLEGAL) and has another downside.. If the parcel goes missing it is not covered for its full amount of value! ( so if you have an $1800 case, and declare it at $999 then you can only insure for $999 and if it goes missing that is all you will get back)