Why do parts manufactured in Australia, cost us so much more than in the USA?

All prices taken from performance part websites.

Example 1 DBA: lets look at DBA 4000s slotted for 07 STI.
In Australia Front (pair) = AUD$440
In USA Front (pair) = AUD$296 (US$306)
That is around 33% cheaper after being shipped to the USA.

Example 2 Whiteline: lets look at 22mm adjustable rear swaybar again for 07 STI
In Australia = AUD$230 (normally around AUD$250)
In USA= AUD$162 (US$167)
Again around 30% cheaper after being shipped to the USA.

I know the Australian dollar is good vs the US dollar so all their prices look good at the moment. However, they are buying them from us therefore currency value should be irrelevant. If our dollar is worth more, it costs them more. They should have to sell them for more.

I have thought of some of the possible reasons:

1. They buy lots more, bulk buy= cheaper price? (I believe DBA have a major distribution company in the US but I don’t think they manufacture)

2. They stocked up while the US dollar was strong and haven’t changed their prices?

3. Retailers here are shafting us? Because there is not as much market competition so they can?

4. Companies are shafting the retailers here and therefore us?

Anyone know why?

If it wasn’t so expensive to ship heavy/large items, you could just buy from the US.
Anyone know any cheaper ways to ship items out other than the usual UPS and USPS?

I was quoted around 500 to send F+R discs and pads, for some reason it’s cheaper to send tires from tirerack than dics etc. I would have thought weight would be in the same ballpark but discs would be a much smaller.

End essay/rant