Early access for Galactic Strongholds is coming August 19th for subscribers (like me). Those who are subscribed before it starts get free access to the Nar Shaddaa Sky Palace, which is 250,000 credits to purchase in game. However, it comes with 3 rooms already unlocked, which is actually a value of 1,500,000 in game credits.
http://www.swtor.com/galactic-strongholds