I use tracfones. I pay $4.99 for the phone. You will need to hunt in yor area for these phones. The price of $4.99 includes 20 minutes over 60 days. When that expires, you can buy a $20 card that last over the course of 90 days. So it breaks down to $7 per month.
Hmmm... seems like online services are much cheaper than tracfones.