most film remastering is done on them, and i would assume at top configuration, they use banks of the things, also for shake on big productions, i.e. Benjamin button. If people didnt want it, they wouldnt make it.
this is an old article but helps: http://www.macworld.co.uk/news/index.cfm?NewsID=14919
The banks are not going to have a large part of the cost of the $22,000: no Cinema Displays, def. not four hard drives, etc.