I have heard otherwise I am afraid! (might be a Canadian thing)
The whole point behind RAID is NOT generally the price issue. (ESPECIALLY now that drives are so cheap)
Large corporations will buy RAID setups for speed and REDUNDANCY. For a server with mission critical information, you would MUCH rather have a 60GB RAID-1 setup (mirrored, so if one drive craps out, the other still contains all the data with no loss of service.)
If they are interested in speed and nothing else, they will go with a RAID-0 setup which stripes the data to two or more drives.
Also, RAID setups (new ones anyways) are HOT-SWAPPABLE. So if one drive in the array craps out, it can be swapped out for a new one and the other drives can rebuild it without loss of data.
If you were a business (I don't care what anyone says, RAID configurations are meant for business, NOT home users) would you care about price? I mean REALLY. You would want the most stable, reliable, and efficient system you could buy. Price would not be a concern, unless the price got ridiculous.
The end.