Have you looked at Virgin Mobile? Unlimited data and 1200 minutes/month for $45. If you want only 300 minutes/month, it's only $35. My wife loves it.
You won't get the fanciest phone in the world, but it's better than paying $80/month for service, IMHO.
I'll second virgin mobile. I switched about a month and a half ago from verizon, and thusfar its worked great. You can still get good phones, just not top end ones. I got an LG Optimus, which works great as a decent little smartphone. I've already got a bunch of apps, and web browsing is pretty good too. As for the network, it works where you'd expect it to work, and doesn't work where you don't. I lose signal in the middle of east bum!@#$, but if you're on a major highway (or route), you'll get a signal. Also, since there's no contract, if you decide it sucks, you can always go back.
As for the cost of the phone, yes, if you get one through the website it's full price, but a bunch of stores put them on sale. As much as i hate best buy, i got my optimus from them when i switched. It was $130, but they had it on sale for $80 and it came with a free $35 virgin mobile top-up card with activation. Since i have the $45/month service, all told, i ended up paying $90 for the new phone and the first month of service.