Recently, a lot of attention has gone to mobile phone plans with heaps of data, such as Vodafone's $130 plan that includes as much as 20GB of data per month.
But what if you're a relatively light user who is more interested in getting as much as you can for as little money as possible?
Here are some budget suggestions. We're not claiming they are the cheapest available, and in any case we don't recommend buying phone service just on price. Generally speaking, you'll need to look at your particular pattern of use and then balance other criteria such as coverage, the availability and cost of data pooling between multiple devices, and the likelihood that the company will sign you up and then pull the rug from beneath your feet by dropping or drastically changing your chosen plan.
1. If you want unlimited calls.
Plans with unlimited standard calls and SMSes start at around $30 per month. Examples include Lebara's National Plan ($29.90 a month, including a fairly generous 2.5GB of data) and Amaysim's Unlimited 2GB plan which also costs $29.90 but appears to disallow business use.
Amaysim uses the Optus network and includes 4G access where available, whereas Lebara uses Vodafone's 3G network - do you want faster data or more data?
2. If you make lots of overseas calls.
Calling overseas can be expensive, but some carriers have plans that make it a lot cheaper. For example, you could justify the price difference between Vodafone's $30 and $50 plans http://www.vodafone.com.au/personal/plans/state/no-plan/multi-fit just in terms of the additional 3.5GB of data, but you also get unlimited calls to China, India, USA, UK, NZ, Singapore, Thailand, Malaysia, Hong Kong and South Korea, along with 90 minutes to other "selected countries."
Lebara's National Plan provides low per-minute charges to some countries such as China, but the 29c flagfall means you only need to make a couple of overseas calls a day for this to work out more expensive than Vodafone.
3. If you need a new phone.
Even though handset subsidies have all but ended it is possible that you'll be better off buying a phone on a plan rather than outright.
Just one example: the base configuration of the iPhone 6s costs $1079 if purchased directly from Apple. Buy it from Optus on a $40 plan and the repayments are $30 a month over 24 months, or $720. That's almost $15 a month less, which effectively means you're paying $25 a month for unlimited calls and text within Australia.
If you're likely to take your phone overseas and you don't like your carrier's roaming charges, make sure you know what's involved in getting it unlocked so you can use an overseas SIM. (Vodafone has a scheme that lets you pay an extra $5 each day you use the overseas and then your normal plan inclusions apply.)
4. The no-plan plan.
Do you really need to be on a plan at all? If your mobile is primarily a way for other people to contact you - that is, you only make the occasional call, send a handful of SMSes each month and rely on Wi-Fi for data, you can save a useful amount of money by using long-expiry prepaid recharges instead of a conventional mobile plan. For example, a $15 recharge from Virgin Mobile lasts up to six months, although once you start making calls to other networks at 78c per minute (28c per SMS) your credit quickly evaporates. It's better if you mostly call other Virgin customers, as then the rates are only 5c per minute with unlimited SMS. No data is included with long-expiry recharges.
Amaysim's As You Go tariff is a bit more attractive if you don't know which nethwork you're calling, because the standard rate is 12c per minute and 12c per SMS. You can pay for data out of your account balance at 7.2c per MB, but by the time you've used 140MB you would have done better to purchase a 1GB data pack for $9.90. This tariff explicitly allows business use.
Both Virgin and Amaysim use the Optus network. If you need or want to be on Telstra's network, Aldimobile's pay as you go plan offers 365 day credit expiry with calls charged at 12c per minute and texts for 12c each, but is 3G only. The acceptable use policy is somewhat vague on the question of business use - it uses the term "commercial use" and specifies that "You must not... run a telemarketing business or call centre; [or] re-supply or resell the service" which we read as meaning that 'normal' business use is OK providing you're not making call after call. But make your own enquiries before signing up.