Why are chocolates more expensive in Australia than in the UK

Does anyone know why chocolate is so much more expensive in Australia than it is in the UK ?

Some examples of prices:

• $ 1.99 Cadbury Flake 30g
• $ 1.99 Frys Turkish Delight 55g
• $ 1.99 Cadbury Boost 60g

These are all shown at the Woolworth’s website 5th Sept 2009.
All three about the equivalent of £1 each.

Then we have the blocks of Chocolate:

• $ 4.30 Green & Blacks 85% Dark 100g
• $ 4.30 Cadbury Old Gold Jamaica Rum N Raisins 200g
• $ 4.30 Kit Kat Dark 170g
• $ 3.76 Lindt Excellence 70% Dark Chocolate 100g
• $ 4.84 Lindt Creations 70% Orange 150g

Is the cost difference due to the economies of scale, not as many being sold due to a smaller population ?
Or is it due to profit taking by the Australian Distributors ?

Even when specials are available, are the Australian prices much more than UK ?

• $ 0.99 Mars bar
• $ 5.99 Mars Celebrations 195g
• $ 5.99 Cadbury Favourites 300g