the tyranny of distance. Australia Post

Now here is an anomaly. I sent something to England. My small package cost $80. To send the same package back to me cost half that amount.? Why?

And are Australia Post really doing a good job when I have lost 

1.  Kobo e reader

2.  Bank pin number letter

3.  Book from Amazon

4.  Letter from Bank

5.  Present from Overseas

6.  Letter from South Australia

And all this in just under 8 months. Where does it all go if it doesn't go to me? I know I'm only one customer but if I am losing this ...well you do the maths per person.