I bought Aperture 3 almost a year ago for 199$ new. Now you are able to go out and download the 559mb installer on the new apple App store for 79.99 with The OSX 10.6.6 update.. Take advantage of this it is a great program you can read my review at Aperture 3 review
EDIT update from John Wallom: Be very careful if you are using this for a business and read the Mac App Store license very carefully. This is not a commercial license for Aperture. The Mac Store license allows you install it on machines owed by the purchaser, and not a business.