Well, so could well be the per minute cost for calling is higher, but there is no monthly service charge. If you use it for just infrequent calls, and stick with texting, it seems to work out good. Texting costs a lot less than calling, plus you have a reliable phone for calling when you need it.
Is way better than still trying to use a pay phone .... whatever that is
!
As far as staying within the usage minutes ..... the phone stops working when the time runs out ..... and it does give a ten minute beep-beep warning.