The monthly plan saves $350 which is 50% off the list price. Outside the cost of the wireless plan, other providers are charging around $21.63/month. Buy Now at AT&T Mobility Tips Requires 0% APR installment agreement with 30 monthly device payments. Eligible for customers w/ select unlimited wireless plans and new line. You'll receive this discount via bill credits, which start within 3 bills. (You'll receive catch-up credits once bill credits start.) The $30 activation fee is waived for online orders. Available in several colors. 64GB for $11.67/mo. 128GB for $13.33/mo. 256GB for $16.67/mo.