I ordered the components of the first Ubuntu Server on FieldsNet today. While I could have probably shopped around for the best possible deal, I went ahead and ordered everything from NewEgg because of their outstanding return, replacement, and refund policies. The breakdown of the machine is as follows:
ASUS M2NPV motherboard
AMD Athlon 64 x2 3800+ 2Ghz
Kingston ValueRAM 512MB DDR2 667Mhz x 2
WD Caviar RE2 500GB 7200 RPM x 3 (RAID 5)
Total cost with case, optical drive, and floppy(RAID install) was $1,150.
While I prefer Intel CPU's, I chose this ASUS/AMD combination because the motherboard incorporated on-board hardware RAID 5 and the AMD CPU is a 65 watt version. I figure that this machine will be on 24/7 so the less power it uses the better. That said, I went with the RAID 5 setup for data redundancy without the loss of speed to only mirroring the drive. This machine will be headless and I may not recognize the hard drive failure immediately.
I expect to get the components later next week and hope to build it next weekend.