I can't believe when anyone tells me that Vodafone sets their data roaming price based on how much the other operators charge for connection - so, Vodafone Australia, Vodafone in Europe, AT&T and Cingular (now just one, the page hasn't been updated for a while), they all charge the same price?
Aha! No, they charge Vodafone NZ a rate of anywhere between NZ$15.00 and NZ$50.00 (or more) per MB. But what Vodafone NZ does is average that price out to NZ$30.00 to make it simple for customers. A nice touch and I don't know of any other operators who do this.
The entire global mobile operator community are colluding on maintaing these insane prices. If the UN had a Competition Commission they would step in and do something! It is up to consumers to show it is unacceptable by using WiFi etc.