Well I guess someone has to say it... How about not worrying about saving $10 or so per month and concentrate on your business? Tough economic times shouldn't be a problem because many businesses, including mine, were started during such tough times and there are still millions of customers for your product or service. I'm pretty sure the easier and simpler solution would have been to make an extra $10 a month and keep using what worked.
Though if you wanted to go even cheaper than TracFone, go with Boost iDen. 10 cents a minute/text, free internet, cheap phones. As far as I know you can even tether to laptops still but iDen is brutally slow for web browsing.