I had been using smartphones for over four years, until just recently. I had an iPhone for two years, and before that I used a Pocket PC that could do everything an iPhone could do except it didn't have such a slick interface. All that time, I had a basic voice package and a decent data plan.
Recently (tough economic times and all) I decided to really have a look at what I was paying for and what I was getting. I found out that more of my "rollover minutes" simply decayed after non-use than I ever actually used. I never used more than 20% of my "evening and weekend" minutes. I never used more than 10% of my Internet bandwidth cap.
Basically, I was paying $85 or so per month and letting most of the value of it go to waste.
So, I switched to pre-paid TracFone. I bought a decent Motorola that has a touchscreen and a decent collection of features. I lost GPS navigation, but that's ok because I have a GPS in my car now. Other than that, I can still talk, text, browse, play games, and anything else I could do before.
The phone came with a "triple minutes for life" deal. Basically, that means that so long as I use that same phone, I buy my pre-paid minutes at $0.047. If I browse the Web, it charges me for the time in minutes, instead of metering my bandwidth. Text messages are about 1.5 cents apiece to send and receive.
And all of it goes over AT&T's network. I have the same service provider as before. Same signal quality. Same Internet bandwidth.
Another thing I did was invest $30 in a decent headset for my computer. When I'm at home, I now use Google Voice to make outgoing phone calls. I get great sound quality and don't pay a penny for it. These are my new "evening and weekend" minutes...
I paid $90 for the phone, and I charged it up with a little under 1300 minutes at a price of $60. That was 2.5 months ago. I still have 430 minutes remaining. That basically means I'm using my phone for a hair under $16.50 per month now. That's a savings of about $70 per month. The cheaper service has already paid for the phone. Anybody want to buy a used iPhone 3GS?
If you use the hell out of your smartphone, you might be getting your money's worth. But if you're a more "casual" smartphone user, then you're getting seriously ripped off.