Actually this is something I'm going to look into closely after today. I caught up with my nextdoor neighbour from our last place today. Rod runs an importing consulting business (BSM Global
www.bbssmm.com ) and has been in the import/export market for 15 years. I asked what it would cost to import at 50kg package of reasonable dimensions costing say AUD $3,000 from the USA to here and he said a surprisingly low number.
I asked about import duties and customs etc, and he said - no declare it as a personal item and you can avoid nearly all taxes and duties...
I'm going to do a follow-up session with him next week, 'cause this is an area I'd really like to understand better.