Hot on the heels of BioShock, Warner Bros. has decided to drop Games for Windows Live support and switch it with Steamworks for both Batman Arkham games. They are also now offered for 75% off on Steam and elsewhere.
It's important to note that as a European, I couldn't even buy Arkham City until now on Steam which was obviously down to Microsoft.
Batman: Arkham Asylum GOTY Edition is 5 Euros while Arkham City GOTY Edition is 5,25 Euros. However, I'm going to buy Arkham City from GetGames, the vanilla version is going for 4,59 dollars which is a lot less money for me due to the exchange rate.