I'm trying to find the cheapest way to use the battle.net SMS protect feature. I have no other reason to get a cell phone, I hate them!

I managed to find a cheap cell phone plan that just requires $9.99 for the phone, and $10 monthly with NO CONTRACT. It auto-charges and adds minutes every month on the account, but there is no penalty for discontinuing the service.

Would this count as a pre-paid phone? Is there a technical distinction that would allow me to figure this out? How would I know if the phone would actually end up working with SMS protect? Am I doomed to fancy expensive monthly plans with year+ commitments, just to receive a few text messages?