I think you are mixing up the two $30 plans. (Yes T-Mobile is confusing, but if you find a plan that fits your needs, then you can save a lot of money

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On "$30 Plan 1," which I believe you were looking at offers a bucket of 1500 minutes/text messages and 30mb of data - this plan sucks. It doesn't offer much value IMO. And other prepaid carriers/ MVNOs have better deals.
On "$30 Plan 2," which I was talking about (see the screenshot attached in an above post" you get 100 minutes, unlimited messages, and 5GB of data at full speed (they won't throttle you until after you hit 5GB). That's a great deal! Most people are paying around $30 for simply their 2 or 3 GB data plan on ATT and Verizon! This includes 100 minutes and unlimited messages. Great for some folks who can live with T-Mobile coverages and limited minutes.