The “Performance Workstation” configuration is the configuration I recommend for computer enthusiast and power-users. If you don't know what either of these are, you probably are not in that group. This configuration is based on the Standard Desktop configuration and adds additional components where performance is enhanced. As of May 2013, the hardware cost of this system was just under $900 with the bulk of the cost going toward the motherboard and CPU.
This configuration would make for a good virtual machine server running Proxmox or Microsoft Hyper-V hypervisors. If you decide to use this configuration as a virtual machine server, double the RAM from 16GB to 32GB.
The software (Windows and Office) will add an additional $250 but if you don't need Microsoft Windows or Office, you can install Ubuntu Linux and get most of the same functionality.