Ok, previous expansions cost about $10 – $15 less than the original… so my guess would be $44.99- $49.99… and for all those saying it should be free… these expansions are no where close to cheap to produce, you are getting a superior product, and these developers deserve our support.
Think of it like this… How much would we have paid in WoW subscriptions over the last 2+ years? This expansion would basically be the same price as 3 months of WoW… whens the last time they did an update?