If you're on a postpaid 3G broadband plan, then it's always tempting to go for the biggest possible download limit. However, that can prove expensive if you don't use most of that data. Planhacker analyses the real cost of choosing a higher download limit by calculating the real per-megabyte cost for different usage levels.
We've recently looked at postpaid 3G broadband plans for Planhacker, but we're taking a slightly different tack here. If you're on a postpaid plan, then your usage is likely to be a little more predictable than prepaid plans, which are useful for intermittent travel use and as an emergency backup (and which we've covered before).
In the table below, we've ranked how much you'll effectively pay per megabyte to the nearest tenth of a cent on contract broadband plans for a range of monthly usage patterns: 100MB, 500MB, and 1GB through 10GB in one-gigabyte increments.
Obviously, if you regularly exceed the monthly limit, it will be cheaper to go to a higher-priced plan. However, if you regularly fall below what you're entitled to, the effective cost of usage can go up significantly, especially on the cheapest plans. We've bolded the price point which offers the best per-megabyte charge at each price level for each carrier.
Making those calculations isn't always straightforward. Shaping is proving an increasingly common option on 3G broadband plans, with Optus, Primus and Telstra all offering that option. We haven't calculated the per-megabyte cost once you cross the shaping limit, since it's not a fair direct comparison: you won't be paying, but you may well be working at less than optimum speeds.
Internode doesn't offer shaping, but doesn't have direct excess usage charges either: instead, users can purchase additional "data blocks" if they go over their monthly limit. We've used these to calculate the relevant costs, choosing the best-priced option for that usage level, which sometimes involves multiple blocks at different prices. This means the Internode prices don't follow an entirely predictable pattern, especially with cheaper plans.
Optus charges $0.08 per megabyte during "peak" periods, and $0.04 during "off-peak" (midnight to 7am), and quotes a total dollar value for each plan rather than a fixed download limit. For the table, we've assumed the higher charge (given the relative unlikelihood that you'll actually be using it during those midnight hours) and calculated how much data that actually gives you.
Click on the link below to access the table in PDF format:
Of course, data cost is just one factor in choosing a provider: network coverage also plays a crucial role. But this analysis does show the dangers in buying a plan that costs more than you need. Given that providers are often happy to let you upgrade to a higher usage level but may balk at reducing your monthly usage, starting on a lower download level may well be a sensible choice — but don't aim too low or you'll also end up paying too much.
As ever, plans with high excess data charges aren't good value. Blink is particularly poor in this respect, and Dodo (which we generally recommend avoiding anyway) is only marginally better.
Hit the links below for the details of each plan direct from the providers:
Spotted a mistake in the table? Got your own metric for measuring broadband value? Tell us in the comments.
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