Hubby & I have a regular cell phone plan, but not ready to add our son just yet. Currently, he has an AT&T Go Phone and we refill as he goes. It is a great way to monitor how much data, text, etc. that he is going thru & how much he'd use if we decide to include him on our plan.
The $25 card is the way to go, if you have an AT& T Go Phone. It is the lowest value card with a 45 day expiration, once activated. Anything less than $25 expires in 30 days. Also, if you use the refill cards you don't have to link your credit card to the account, plus get Best Buy rewards for the base amount...bonus. We live in CA, so when you buy the card there are taxes and fees added to the amt you have pay. =(