Cheap Space
A terrabyte of disk space for under $1200? No problem...here's the recipe:

1) 5 Maxtor 300 GB hard drives ($130, last time I checked)
2) 1 LSI Logic MegaRaid Sata 150-6 PCI Raid Controller ($300)
3) A case with SATA power connectors ($70)
4) A motherboard so that the case will power up ($130)

Total cost $1150

In my case, I had an old PII. I bought SATA power adaptors from CompUSA, took everything out of the case except the motherboard (including CPU and memory) then installed the drives. The MegaRaid comes with 6 1 meter cables which I from the drives out the back of the case. I installed the MegaRaid adapter in my server (an old Compaq), and ran the cables in through a slot in the back. There is BIOS software in the adapter that makes it very easy to configure the drives. I did so, formatted them and now have lots and lots of cheap RAID 5 space.

For the LSA Logic MegaRaid Sata 150-6, try ZipZoomFly:
http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=132610

For Maxtor Drives, try ZipZoomFly:
http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=100719-4

For SATA power adaptors, try MonoPrice:
http://www.monoprice.com/products/search.asp?keyword=1253