Those are all base union (pro) rates...in other words, you can find a guy with his own equipment, and get him for free (we do). Just so you know...they are out there.
Crew that don't work movies full and hold a 9-5 (like most of us still do) are in it to build their resume, and expand their horizon and skill...many feel lucky they are working on a competent set, and will work pro bono or for very little.
Often times, we don't have an external sound guy. We have a boom op that plugs directly into the camera. Sound horrible? Nope...the sound turns out just fine every time. (example:
http://www.youtube.com/watch?v=t5yBfouKhXw).