Really Large Cheap Storage

Promise's SX8000/RM8000 unit which holds (8) IDE drives in a RAID5 configuration, total cost for 1.5Tb of storage was $3.44/Gb.

Well, they also make an RM15000 unit ($4000) which holds (15) IDE drives. Figure (1) drive for the parity bit and (1) drive for a hot-spare and you have theoretical capacity of 3.17Tb at a cost of $2.62/Gb. Using the 160Gb drives (currently $160 each in bulk) you'll end up with a 2.03Tb array at a cost of $3.08/Gb.

FYI, the largest SCSI drive on the market is 180Gb at a cost of $1300 each, so figure the cabinet and hardware to hold the drives would be $2000, and total drive cost of $19500. Resulting cost for 2.28Tb of storage is $9.21/Gb -- which is 3x the cost of the equivalent IDE solution. But the SCSI solution is more suited for primary storage (speed, reliability, warranty).