In a post on the EU forums, Blizzard delivered the bad news: “We regularly look at our pricing around the world, and from time to time we make changes such as these to align with local and regional market conditions. The price of the Un’Goro prelaunch bundle offer will not be affected by this change and will remain the same until launch.”
Polygon notes that the prices for affected customers are going up about 30%. The increased prices will affect players in Europe, the Middle East, and Africa starting March 22nd.
Source: Official forums via Polygon