It's show $59.99 on Amazon.com, which is how much a standard PC and PS4 game cost this day. They say Heavenward is like a new game with as much content as ARR, so it may actually cost this much.

http://www.amazon.com/FINAL-FANTASY-XIV-Heavensward-Windows-Pc/dp/B00OM6SAK0/ref=sr_1_1?s=videogames&ie=UTF8&qid=1417915616&sr=1-1&keywords=final+fantasy+xiv+heavensward