Here's my understanding of wap browser charging
voda casual rate $0.10/10kb .. ,,
and you can buy bundles of traffic, e.g. 3MB for $10, 15MB for $39, through to 1GB for $50
http://vodafone.co.nz/pricing_plans/mobile_data.jsp?item=mobile_data
tcom casual date is $0.05/1kb
and it seems you can't buy bundles of wap browser traffic.
http://www.xtra.co.nz/mobile/0,,10311,00.html
have i got that right?