It appears that, with Aperture on the Mac App Store, Apple is moving to the same kind of pricing model that pertains to iLife; make it cheap enough so that yearly (roughly) paid upgrades are palatable.
Final effect is similar to a subscription model; the vendor gets a steady stream of income, which all businesses crave. Wonder how Adobe is going with its subscription offerings?
And think about what the Mac App Store means to all vendors, including The Mothership; a central repository which can be searched, and downloaded from. No more cardboard boxes, CD or DVD media, Kagi accounts or shelf space needed. Interesting that Aperture is still available from the Apple Store for $199, rather higher than $79!