The official mp3pro website quotes licensing rates of about 50% higher than mp3, as I remember. This isn't a lot of money - we're talking <$1 extra. I can believe $7 for an *encoder* though.

As for the sound quality - have you tried the demo? It's very impressive. Even John was impressed :)

There's no DRM in it - avoiding mp3pro because it might get wrapped in a DRM layer is the same as avoiding ogg vorbis because it might get wrapped in a DRM layer. You could do it with either, but neither have any specific concessions to allow that.

Hugo