I need underexposed footage fixed

I need some underexposed footage fixed. It's raw footage right now (about 70 minutes) and will be edited into a 20-minute simple edit.
Fixing the underexposed bits could be done pre- or post- edit as suggested?

Below is a link to the footage.

If my price is too low, please suggest a counter offer.

Furthermore, there is a white speck on a the t-shirt of the therapist in the video and I'd like to get this blurred out.

Download link for sample of the shots:

http://www.mediafire.com/watch/z3cldy3x84928jr/underexposure_sample_.mp4