$11.99 on Steam
$9.59 on GMG after Coupon
Original Thread, covers the registry leaks and speculation that lead up to the release.
UPDATE
Game does not have the always-online DRM, Securom, or Digital River install limit that the Square-Enix store version had.
There is a one time login to a Square-Enix account when you first run the game, then you are free to run offline.
No Securom confirmed by Xelios via the registry.
Only installed Microsoft VC redist packages or whatever.
Upon launching:
MODS
Anxious Heart (No longer required after patch)
Anxious Heart replaces all the music with more high quality tracks. LegacyZero uploaded the mod to an easy Google Documents download.
Tifa's Bootleg
Tifa's Bootleg patches the game so it is functionally the same as the 1998 release, you lose things like Achievements and Cloud Saves, but gain the ability to massively mod the game. Download comes with player models, properly upscaled backgrounds, new menus, etc.