MP3 Encoding Royalty rates on iPhone apps?

I have seen several iPhone applications that support mp3 encoding, and some cost less than $3. The mp3 minimum royalty rates that are on the licensing page: http://mp3licensing.com/royalty/ seem to suggest that such a price is simply impossible IF they are actually paying their legally required royalties, even if just for the patent-only (user-supplied source, probably lame or some such) rate. Are all these apps just hoping to fly under the radar? This seems like wishful thinking. Either that, or I am missing some part of this equation.

I have emailed a few of the creators of such apps asking what sort of licensing scheme they have managed, but none have responded.