FMOD license issue

Hi everybody. I’m new to Unity, and I have just downloaded the free version (I can’t afford the Pro right now), and I have seen that it uses FMOD, a very expensive audio library ($3,000). I want to make a commercial game (very simple and nice, that doesn’t needs surround, filters, or other audio tricks, only pure,classic stereo), so, I want to ask :
¿Can I use the FMOD with Unity for free?
If not ¿Can I use another audio manager (OpenAl, or another that you recommend, and I would prefer a free one)or is there a way to work around this problem?
I really, really want to use this engine, but until I sell some copies of my game, I won’t be able to afford the Pro version nor FMOD.Please, respond. Thanks.

You probably will not need FMOD: Unity has its own builtin audio library, which from my point of view is good enough for most cases. You can have 3D sounds (sounds that are originated at specific 3D points) or 2D sounds (regular stereo sounds not attached to any particular point - like a sound track, for instance). Presently, the Unity audio engine can’t access audio inputs like microphone or auxiliary - but rumor has it that in the 3.5 version this feature will be available.