Why would someone just buy drives like that? If there is that large of a need for space, go buy a good array from Sun, NetApp, Hitachi, IBM, EMC, or a smaller vendor. Let them do the testing, warranty work, and integrity and let you work on your business. What do you do if you need more space than a DAS RAID can fit?
With iSCSI, FCIP, FOE, 10GbE, and FC being much cheaper/free than years ago why use DAS disk? Slice those big drives into RAID 6 and then into whatever sized LUNs you need. 5GB for a boot? Well you can fit 200 onto a RAID group. Need a 5TB Lun with good speed? Grab 1TB from several different RAID groups and have the array controller stripe for you. 8Gbs FC is out now, 2Gbs FC is really cheap with used equipment. iSCSI is pretty much free. You can even virtualize whole arrays so if you give someone 1TB and they only use 5Gb, only 5Gb is actually in use on physical disk. If you buy a deduplicating array it'll even eliminate redundant information for you depending on how you set it up.
If you value stability, flexibility, and redundancy and don't like employees wasting lots of time on hard drive testing and fixing, go buy the right tool for the job. Large arrays are also usually 'greener' since they can use drives much more efficiently if set up correctly. One 15K RPM 300GB FC RAID set at full IO load can beat hundreds of cheap SATA drives at low utilization for IO. If space is there problem then there are ways to work that too.