Hands down the best prices in unmanaged servers:
http://www.rackshack.net/english/all.asp
Sample configs:
Intel Celeron 1.3 Intel Celeron 1.3 512MB 60GB 10Mbps Ensim Details $349
Intel Pentium 4 Intel Pentium 4 2.0 1 GB 80GB 10Mbps Ensim Details $399
Intel Pentium 4 Intel Pentium 4 2.0 1 GB 80GB 10Mbps Ensim Pro 250 Details $399
Intel Pentium 4 Intel Pentium 4 2.0 1 GB 80GB 10Mbps Cpanel Details $399
DELL DUAL XEON Intel Dual Xeon 2.0 1 GB (2) 73GB SCSI 10Mbps Ensim Pro 250 Details $499
DELL DUAL XEON Intel Dual Xeon 2.0 1 GB (2) 73GB SCSI 10Mbps Cpanel Details $499