Personally I think there are two possible reasons they're not charging for it.

1) because they know that if they did there would be trouble because they know they can't devote enough man-hours to the project to deliver something worthy of charging for... (Think about it. NO listed company would release something for free if it was worth paying for).



Or



2) I was talking out my Asp in 1) and they are in fact going to continue to rely on micro transactions like the successful raider kits from here on out and move to a F2DLC model.