If i was to buy a jetski from canada or america and i live in sydney australia do i have to pay for any taxes?

Question

or pay for anything else apart from shipping

Answer 1

you will probably pay import tax

Answer 2

You would pay about an extra 15.5% on the total cost including shipping.

The current information from Australia Customs is that goods valued at UNDER $1,000 are free from Customs Duty and GST. (Last checked June 2008). Note: special rules apply for Alcohol and Tobacco products.  

Purchases over $1,000 will incur Customs Duty at 5%, plus GST at 10% on the combined cost of the goods, the duty and the delivery charges.