This could be of interest:
http://www.customs.gov.au/webdata/re...ff/ht90aw1.pdf
Reference 9005.80.000.
Spoke to someone in Customs and there is no customs tariff for telescopes over $1000. You still need to pay GST. Then there's Customs Broker, insurance.....
Outside of losing potential warranty, I'm wondering how much you would really save when buying a scope overseas ??? Has anyone tried or done it before ?