I have t-mobile and want to get a Blackberry Pearl Flip. Right now I have the Samsung Gravity 2 and don't have a data plan (internet plan). If I bought the blackberry off ebay, would they require me to get a data plan? All I want to do is call and text. And the phone has wifi so I would be able to go online for free. Also would I still be able to go on aim and get picture messages because I have unlimited texting? Please & Thank You.