Over the years, I have bought almost all my scopes from the USA. I have never had a problem, although they have all been refractors with the exception of a 10" Meade S/C. Refractors tend to be more robust, and are not so easily damaged by mishandling-still, I have never had anything damaged in shipping.
I find US dealers very good to deal with, and I have never had my credit card refused.
If the combined cost of your purchase and freight is under A$1000.00, you will pay no GST or customs clearance fees.
I do support local dealers by buying accessories from them, however.