avoid paying tax but paying additional shipping cost?  

How come u have 2 parcel shipped on same day? Seller didn't pack it together in 1 pack? Or u buy thru agent? My seller used to ship 1 big boxes inside content 6 boxes of figure without any problem. I have another 6 boxes of pvc figure coming soon. 3 from Amiami, 2 from HLJ and 1 from JATO. Hopefully all can arrive with safe without kena tahan by kastam.....

Quite often. The kastam become more strict compared to before GST

Now I've to figure out ways to get this past the kastam
I thought i wont need this figure, i was wrong. Looked nicer than expected.

Yes, mainly luck. I'm ordering her from Nippon-Yasan instead this time because underderclaring  (low value) will attract less attention, and a sitting figure does not have a big box. The signs are there - EMS is rated at 2400yen, that means same box size as Tougetsu Matsuri, which isn't big.  I'm taking my chances.

Regarding Australia, currently only packages exceeding AUD$1000 gets taxed. The bad news? From 1st of July 2016 onwards, all packages regardless of value, will be charged 10% GST. Their tax payment system is different - from what my Australian friend said, they record all your imports and their tax amounts, and total them up. Then you pay your taxes annually. The good thing, no need waste time at kastam; the bad thing = if you dont keep track of your purchases and be prepared for it you will face lots of taxes to pay by year end, an accumulated amount over the course of 1 year can be scary.