The Titanfall original soundtrack is available as of today for purchase at a pretty modest price. After all, any true Titanfall fan would never want to be separated from the game, and music is a pretty good way of staying connected no matter where you are.
The soundtrack spans a total of 18 tracks, and both Amazon and iTunes have the entire OST listed for just under $10. If you grab the OST from Apple, it's $9.99; Amazon.com is selling it for $9.49. Both outlets priced the individual tracks at $1.29, so I'd say grabbing the whole thing is a better deal.
Titanfall's OST is credited to composer Stephen Barton, and for those who have no idea what the music is like, just imagine ambience for any sort of modern shooter. What I'm trying to say is that the soundtrack is very good.