Basic server - $500
This server comes with the minimum entry-level functionality to get a small workgroup of PCs and Macintoshes collaborating. Packages include: file sharing (NFS, SAMBA and AppleTalk), email server with POP3, print server, and a web server (Apache with either PHP or Perl).
Premium server - $900
The big guns. This has everthing the basic server has, plus a firewall, FTP server, secure web server (Apache/SSL), secure email server with spam protection and IMAP, and two networked databases (MySQL and PostgreSQL),
The fine print
Prices listed are exclusive of hardware procurement costs. Customization can be done at $100/hr.