[tarice]

I look at it this way:

Plan #1: $30 for 100 minutes, with $0.10 a minute afterwards.

Plan #2: $40 for unlimited minutes with MetroPCS.

So, if I manage to talk less than 100min + ($50 - $40)/$0.10 = 200 minutes per month, then I end up spending less than I would on the MetroPCS plan.

[Fundlab]

I talk well over 300 minutes a month but I get your point