While T-Mobile USA has long offered some of the cheapest and most liberal smartphone data plans in the wireless biz, it’s data plans for tablets and laptop dongles have always left something to be desired. On Wednesday, the carrier revamped its mobile pricing structure, introducing a new 500 MB tier, adjusting some tier prices and adding a new category of unthrottled data plans. The changes aren’t revolutionary, but they will certainly give T-Mo customers more options.

T-Mobile is still offering “classic” and “value” plans, with the latter charging cheaper rates to customers that buy or bring their own devices. But T-Mobile is further subdividing those categories into consumer and business plans. The consumer plans are subject to T-Mobile’s normal soft caps, meaning speeds will be throttled back when customers reach their monthly data allotments. The business plans, however, won’t be throttled. Instead, overage fees ranging from 2 to 10 cents a megabyte will kick in when the hard cap is exceeded.

While any customer can buy either plan, T-Mobile said the overage-fee plans are targeted at business customers who need to keep their high-speed data connections at all times. There’s an advantage to signing up for hard-capped data though: the business plans are between $3 and $5 cheaper than their consumer counterparts.

Apart from introducing the new 500 MB tier — which costs between $20 and 30 depending on the plan — T-Mobile has also tinkered with its existing plan pricing, adjusting some rates upwards and others downward. For instance, you’ll now pay $2 less if you sign up for a classic 2 GB plan ($38/month), but you’ll pay $2 more than you would have previously if you take the equivalent value plan ($32/month).

The end result is that T-Mobile’s value plans are becoming slightly more expensive, which runs counter to its stated policy of driving more customers to an unsubsidized handset model. T-Mobile also launched new prepaid pricing plans last month.

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