T-Mobile offers two types of plans, the Even More Plan, and the Even More Plus Plan.

The Even More plan is for people who purchase discounted devices with two-year agreement. This plan costs $10-$30 more per month than the Even More Plus plan in order to make up for the cost of the device. For some devices, it’s actually cheaper in the long run to buy the device at full price and save the $10-$30 per month.

Over the course of two years, just $10 extra per month comes out to $240. For some devices, you can save more than that with the two-year agreement, but others might be discounted less.

For instance, if want to have a family plan with 3 lines, one being a smartphone and the others being regular feature phones, the Even More plan will likely be $30 more expensive than the Even More Plus plan. You could get the two feature phones for free (saving about $100 on each) and the new G2x for $200 (saving about $250). The two-year agreement will save you about $450 on the spot, but cost $720 more over the course of the full two years compared to the Even More Plus plan.

Often times the overall price comes out close to the same, but it does vary from situation to situation. It’s smart to do the math and see which works out best for you.