Search:

First I know nothing about Rod's module
But on a total sales price of $116.05
The gst included in the price is 116.05/11 = $10.55

The only way to get $11.60 is 116.05/10 (which is incorrect)
...

Lets play devil's advocate here :)

I decide to sell my fabulous new mousetrap to overseas customers for $100 (no gst)

I also decide that I don't want to disadvantage my local customers by...

Or..........
You could charge the same price for Oz and for O/S
The Oz sales include gst (so you have to pay the gst)
The O/S sales have no gst component so you make more profit
You don't have to...