How Much Do Phones Cost Per MonthU_dc3w-" referrerpolicy="origin" target="_blank">See full list on lifewire. Cell phone plans can cost anywhere from $30 a month to $150 a month depending on the features included. The 5G Play More plan starts at $80 per month for a single line but drops to as low as $45 per line if you have four lines on the plan. One line costs $85 per month, two lines are $70 each, and a third line is free.