I guess it will be charged but not much. In my country you can find FFXIV for PC at 12 euros in stores. It's really cheap. They made this game cheap in order to bring more people to it. I don't think they will charge 40 and 50 euros/dollars for the expansion. There is a high chance it will be a free update though I'm not expecting this. It will be a pleasant surprise. Considering how much big the 3.0 will be I bet it will be a charge. Time will tell as we know nothing about it just yet.