Is it just new packaging? I noticed the last time I bought some it was a different bottle but the conditioner seems just the same. I would go with the cheaper option, they're probably trying to get rid of the stock with the old packaging.
I buy it from iherb, it's cheaper and the postage is pretty good (so long as you aren't in a hurry).
There has only been a slight variation with the formula of GPB conditioner. Apart from Witch hazel extract being removed and Castor oil being added there are just a few minor changes in the order of listing of the ingredients.
Fine 3B/C curls.
Currently growing out damage caused by straightening and coloring.
The last bottle I got was the new design, so I'm assuming the new formula, it didn't seem any different to me.
What's the postage like on the Australian site? If the dollar keeps going down I may have to rethink my overseas shopping habits.