3G is not worth it, you dont really need internet on that thing except to download new games and sync trophies, and you can do that at home. Follow the advice and spend the money on a 16GB memory card.
I originally planned on buying an Xbox One but didn't do so after they announced all these restrictions. Instead i preordered a PS4, but still wanted to eventually get an Xbox One for Halo and stuff, and to show them how I approve of this change, I just also preordered an Xbox. Same thing as Vinny.