I am thinking of buying a second hand blackberry, as some months I'll need to use email on the move. I have a bog standard nokia on 02 payg at the moment, but I have just got a free giffgaff sim card and when needed I can choose to have a bundle with internet. I've seen unlocked and refurbed blackberries on ebay. How old can a model be so that I still have reasonable internet (as I am giffgaff I won't be using the push email or bbm functions)? Or is this a dreadful idea from the get go?