Vodafone and Virgin Mobile will go head-to-head in a bid to lure data-hungry purchasers of the Samsung Galaxy S III.
Vodafone immediately made a headline play for the hungriest data users by offering to double data quotas for the first year on a range of its 24-month plans.
The double-quota offer made Vodafone's plans largely competitive with those of rival Virgin Mobile, whose plans could be augmented with data quota add-ons to come out roughly on par.
8GB for the same price
On its fattest $99 Infinite plan, Vodafone effectively offers a 8GB data quota for the first year, reverting to 4GB for the second year.
Back-of-the-envelope calculations show it is possible to achieve the same data quota - at the same cost - with Virgin Mobile.
Vodafone lists the total minimum cost of its $99 a month plan as $2376, which includes the first year of "doubled" quota to 8GB.
Virgin Mobile's high-end $89 a month plan comes with 4GB but it can be doubled to 8 GB for a "fixed" 12-month period on the carrier's online store for an additional $20 a month.
As the total minimum cost of Virgin's plan over two years is $2136, adding $20 a month for the first year pushes the total cost up to $2376 - exactly the same total minimum cost as Vodafone's offer.
Virgin also comes out ahead of Vodafone at the low-end $29 a month price point.
The base $29 plan by Vodafone comes with an additional $20 monthly handset fee, 400MB of data for the first year and a minimum spend of $1176 over two years.
Virgin Mobile offers several $29-a-month options with varying handset fees.
Virgin's $29 a month 'Fair Go' plan has an additional $18 a month handset fee and 250MB of data for a minimum total cost of $1128 over two years.
Virgin also has a $29 a month 'Big Plan' with an additional $20 handset fee that comes with 2.25GB of data and costs a minimum $1176 over two years - the same cost as Vodafone, but with substantially more data.
Ordering before midnight July 1 qualifies the user for a bonus 2GB data "every month for the life of your plan", Virgin's website states.
So Virgin users concerned with data quota could end up with over 4GB a month for their entire plan, for the same price that Vodafone users pay for 400MB for half their plan's duration.
Telstra and Optus?
Optus' largest data quota is 3GB in its $99 a month plan for new and existing customers, at a minimum total cost of $2178 over two years.
Its cheapest offer is $50 a month with an additional $12 monthly handset fee; that comes with 1GB of included data and costs at least $1388 over two years.
For existing customers, Optus has dropped handset repayments on its $60 a month plan and also cut the repayment on the cheaper $50 a month plan from $12 to $5. The standard two months free access for ordering Optus services online also applies.
Including handset repayments, Telstra's plans range from $72 a month (with 1.5GB of data) to $129 a month (with 3GB). Those translate to minimum costs of $1728 and $3096 over two years respectively.