The latest Time magazine has an article on the VFX business. Very worth reading.
"A major point of contention between VFX shops and studios is the issue of change orders. When a director revises what he wants to see in a shot, it can mean months of lost work. Under the current system, most VFX houses feel they have to eat the costs to maintain their relationships with studios and filmmakers."
Richard Keerigan also had blog posting about VFX work here in California.