Telescopes attract a 10% import tax into Aus. That is 10% of the item cost + 10% of the shipping/handling costs (oh I should have said this is really a GST charge)!
Most items are sent to Aus by UPS/DHL...what ever. These companies usually process all the import paperwork & charge you: import duty tax; and a customs a handling/processing fee.
They usually contact you when the item is in bond store & tell you to pay $xxx amount. They do not usually give you a breakdown of the frees & charges so you just suck it up. You eventually get a receipt from them outlining the costs.
If you use USPS, there is no "customs handling fee" etc....I believe...maybe someone else can correct me on this? With this you probably have to declare the goods yourself & fill out & send the forms....as you said.
So try to use USPS...but I don't know about package handling & insurance & tracking with USPS.
I assume you are intending to buy from US?
Customs import
fees really are a nightmare!