I asked this once already, but I'm still unsure. I bought a BlackBerry Curve from ebay and was wondering if the SIM from my V3xx Razr will work in it? I have AT&T and the Blackberry is locked with AT&T. Will the switch change anything with my current cell phone plan? I have 450 minutes/month and 1500 data/text messages. Also, I heard data messages cost more with the blackberry cuz it's a smartphone. Is that true?