The official Street Fighter IV costumes from Capcom are paid downloadable content (DLC) available for the PC, PS3, and Xbox 360. For the Xbox 360, the packs for all SF4 characters cost 1000 Microsoft Points combined, or 320 Microsoft Points for just the Femme Fatale Pack, The individual Femme Fatale Pack costs $3.99 for PlayStation users, for comparison. PlayStation Network and Xbox Live users simply have to use the PlayStation Store and Xbox Live Marketplace, respectively.

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All the official Street Fighter 4 character costume packs, including the Femme Fatale Pack with Chun-Li costumes, are available to users through the Games for
Windows Live Marketplace, which require a free Windows Live ID Account. The packs cost 320 Microsoft Points each, just like on the Xbox Live marketplace; about $4 U.S.
Also available for PC users are user-designed costumes, which can be downloaded from a number of the Street Fighter IV fan and modification sites in the SF4 community. To install these custom alternate Chun-Li costumes, or any others, navigate to the “CAPCOM\STREETFIGHTERIV\Battle\” folder and then open the folder for the character you want changed. Make back-up copies of all the files in the folder, in case there is a problem and you need to revert to the original skin. Now copy the .emz files you downloaded into the folder, and the new skin should now be available in the game!