By cost-based pricing, I'm assuming you're referring to the operators costs? IMO, this is far from ideal and Vodafone's price plan is simply another variation of volume-based pricing that consumers simply don't understand and can't be expected to.

There are so many catches for the consumer with this plan that I don't see it as an improvement at all. IM & VoIP traffic charged at a higher rate spell protectionism loud and clear and the 15MB daily limit is all too easy to exceed even with browsing..

Sim:

Ignoring the free 14.5 MB per day, the price for web access is the same as that for VoIP/P2P traffic. Indeed, if the 2 MB that they are counting is only download bandwidth consumption, then the rate becomes half of the web access charge. I am attributing the free 14.5 MB of web traffic is their way of encouraging web access by mobile users.

I used a wrong phrase when I said "cost based pricing". I should have said that their data pricing plan is independent of application, even though it seem to be that way. Again, I can say that because I am ignoring the 14.5 MB download they are giving it away for free.

Just for the record, I compute the charge for one minute voice call to be 12 pence (or 24 pence, if upload bandwidth is measured as well) per minute if one uses data tariff. (8 kbps codec will use 60 KB per minute).