Isn't it a well known and often documented (all over the internet) part of app marketing that setting the right price and the right monetisation strategy is important.
Altering the price of an app is extremely common, i would like to say at least 50% of apps have changed their price in their lifetime, but that is just a made up number.
Personally, i quite liked the look of Traktor when i browsed a while ago, but i knew i would not use it much as i have no musical ability whatsoever... i didn't buy it.. today i downloaded it for free. So, to the app developer, the consolation of free is increased users who are now much more likely to be future customers.
I also play Asphalt 7 .. which is free but was about £7 ... shall we bash Gameloft?
This is not really a story.