Rocksteady has revealed via
Twitter that you will be able to purchase Harley Quinn's Revenge without purchasing the Game of the Year addition on X-Box Live and the PSN for 9.99 [800 pnts]. Here's an offical
FAQ [Note: they've also revealed that the pesky save bug has been patched]---
HARLEY QUINN'S REVENGE
How much will it cost?
800 points on Xbox Live and $9.99 on Playstation Network
Do I need to buy the Game of the Year edition to play it?
No
Do I need to own Arkham City to play it?
Yes
When can I buy it on its own?
From May 29th onwards (both Xbox Live and Playstation Network)
Is it coming to PC?
Yes, we will be announcing more details soon
Are there new achievements?
Oh yes!
Who do I play as?
You will switch between Robin and Batman within the DLC.
Do I need the Robin DLC to play Harley Quinn's Revenge?
No
How long is the content?
Over 2 hours and all new environments
Are there any Easter eggs?Is this the last DLC?What are you doing next?
You will have to wait and see!
Batman: Arkham City is a 2011 action-adventure video game developed by Rocksteady Studios. It is the sequel to the 2009 award winning video game Batman: Arkham Asylum, based on the DC Comics superhero Batman. The game was released by Warner Bros. Interactive Entertainment for the PlayStation 3, Xbox 360 and Microsoft Windows. The game was officially announced during the 2009 Spike Video Game Awards and was released worldwide for consoles, beginning in North America on October 18, 2011, with the Microsoft Windows version following on November 22, 2011. A Wii U version is set to be released in 2012. A spin-off iOS game, Batman: Arkham City Lockdown, was developed by NetherRealm Studios and released on December 7, 2011.
Arkham City was scripted by veteran comic book author Paul Dini, who also scripted Arkham Asylum. It features a main plot and side-missions that develop their own sub-plots. The main storyline revolves around Batman's imprisonment in Arkham City, a sprawling new super-prison five times bigger than the original asylum and enclosing a wide variety of industrial districts, iconic locations and Gotham City landmarks. He must now stop mishaps occurring around this chaotic enclosure caused by Gotham's most notorious super criminals. The game has received universal critical acclaim and is one of the highest-rated video games of 2011 according to review aggregator Metacritic.