RAID 0 is an option for people who want to BUY (2) inexpensive disks and combined them so the OS thinks they have 1 large drive. For Example: A Seagate Barracuda 400GIG HDD with NCQ is $330.00. But, if you buy (2) 200GIG Seagate Barracuda with NCQ they are $125.00 that's $250 for 400GIG in RAID 0. You just saved $80.00.
And as far as performance goes, RAID 0 doesn't universally increase performance, i've read serveral articles and benchmarks that all showed that performance increase all depended on what chipset RAID 0 was run with.
RAID 0 is just a good option to buy (2) less expensive disks and combined them to have one large storage area.
Google : Performance increase in RAID 0
You'll find what i've stated here.