I definitely don't have access to a few million dollars. But you never know what's around the corner.....
Well, if you ever find yourself with a few million dollars burning a hole in your pocket, I'd put setting up an MVNO well down the list!
If you are interested in seeing how many MVNOs you already have in Australia have a look at the list on this Wikipedia page; https://en.wikipedia.org/wiki/List_of_Australian_mobile_virtual_network_operators
However, I liked the way giffgaff operated when I was in the UK and would like the same in Australia. It's obviously not going to happen for a long time. Thanks again for your input.
No, there's no likelihood of giffgaff spreading outside the UK but there's nothing to stop another operator setting up a network based on the giffgaff crowd sourced model.
You never know...