Original Link: http://www.omnigroup.com/blog/entry/update-no-upgrade-pricing-for-mac-app-store-purchases

Ken Case:

My apologies: I’m afraid we will not be able to offer upgrade pricing to our Mac App Store customers after all. So long as we continue to sell our apps through the Mac App Store, we are not allowed to distribute updates through other channels to apps which were purchased from the App Store.

It would be really nice for Apple to finally add a paid upgrade mechanism to the App Store, but it doesn’t seem to be something they want to deal with….