Some good leads here - thanks indeed. I have trouble converting rates between Gb and Mb, so I have put them into a spreadsheet and found the rate per Gb, and charted them. All rates are in $AUS, and I converted rates as required.
Note that the scale is necessarily logarithmic (because some international roaming charges are obscenely high), and this makes them look more comparable. However the true difference between the various providers is enormous. The cheapest by far is the fixed line ADSL2 connection in Australia which is $0.66 per Gb. The most expensive is Telstra Australia international roaming which is $3,000 per Gb.
