I'm considering buying a SMS module, but the cost is a little intimidating. Knowing about a power outage and being able to respond is priceless though.
Couple questions maybe people can help me out with.
With a SIM card - how long do they last before they expire? I.e., if I bought a $20 card, does it last until the money is used up, or in general, do they have an expiration date? Any recommendations on a company that sells them with good terms?

Does it come with a PAB cable or is that an additional cost?

How long does the battery in the module last?

I'm a little nervous about spending so much just for power outage notification, ya? I basically have my p3 connected to the internet now so none of the other SMS functions are valuable.