The Petra Zone

Looks like Classic Petra is available on emusic as well as Itunes. On emusic they have BTTR listed as Petra, there is no Classic Petra listing. The entire album is $6.99, dirt cheap.

http://www.emusic.com/album/Petra-Back- ... 36377.html

With the services available now, if you get on iTunes, you will likely have the option to be sold everywhere. All any artist has to do is join CD Baby, Tunecore or others. So, expect to see it on all of the legit services and even on those that are not, including bit torrents.