If you use a lot of mobile data, it can be attractive to go all-out and find a plan that has extra capacity over what you'd usually use. Having the freedom to browse the 'net and download and not limit yourself can be a liberating experience. There are times when you should hold back, though — it just doesn't make sense to buy Telstra's two most expensive mobile broadband plans.
Update: Telstra has been in touch with us to say that the cost of the 25GB plan over 24 months is actually $165 per month, rather than $175. That changes the price to $6.60 per gigabyte, and therefore makes it actually better value per gigabyte than the 8GB and 15GB plans. Here's the updated pricing — $105p/m for the 15GB plan and now $165p/m for the 25GB plan.
Telstra's mobile broadband, data-only plans are on the more expensive end of the 4G spectrum (excuse the pun) in the first place, but some are better than others. There are four plans listed on Telstra's mobile broadband website, with a maximum 15GB for $105 per month, but there's a hidden 25GB plan — at a painful $175 per month on a 24 month contract.
(As a point of reference, Vodafone offers a 25GB data-only mobile broadband plan for $90 per month. Just in case you were looking for a comparison of the value you can get from different carriers. Going with Telstra is a great idea, though, if you want access to 4GX, Telstra's new long range and high next-gen 4G network.)
The problem is, that $175 25GB plan isn't even good value. Whirlpool user KaZZ0 has done the maths. If you're looking for data only — this is for a tablet or hotspot, not a smartphone — and you're willing to commit to a full 24 month contract, data becomes cheaper as you commit to purchasing more — usually.
1GB of 4G quota on Telstra' mobile broadband contract costs you $25 per month, so that's $25 per gigabyte. 4GB is $35, and $8.75 per gigabyte. 8GB at $55 is a comparatively cheap $6.875 per gigabyte. If you want a 15GB or 25GB mobile broadband plan, though, you're back up to paying $7 per gigabyte, on the massively expensive $105 and $175 monthly payment plans. Surprisingly enough, the middle of the road 8GB plan is the best value, instead of decreasing in per-gigabyte costs as you purchase a larger quota.
One important note — if you're a business user, you can purchase Telstra's 4G data plans through BigPond. The big difference here is that once you hit your data quota and start to exceed it, your connection will be shaped — slowed to a predetermined speed — but you won't be charged any additional costs for your downloads. This is distinct from Telstra's customer plans, where there's no speed shaping but you're charged 3 cents per megabyte of excess data used.
Unless you really, really, absolutely need that extra data, there's no rational reason to commit to Telstra's 15GB or 25GB mobile data plans, especially for such a lengthy contract period — you'll be paying more per gigabyte than if you were more moderate with your usage on the ideal 8GB tier. It really seems like Telstra is charging extra for the privilege of having a larger data quota, which is disappointing. It's one of the few things keeping plenty of Aussies, including myself, from switching from our decrepit ADSL2+ connections to 4G during the long, long wait for the NBN. [Whirlpool]