Batman: Arkham Asylum will be available in Collector's Edition form for a whopping $100. That's $40 more than the normal edition.
The CE contains a 12" Batarang, DC Custom Encyclopedia, DLC Pack One, Bonus DVD with behind the scenes features and a soundtrack.
This information was provided by GameStop, but according to Kotaku the listing has since changed to: "Final contents of collector's edition are to be determined."
Interested parties may want to hold on a bit longer, just in case more goodies are to be included. Or removed.