Update: Free additional 16x DVD-ROM now.

Dell Business has this Dimension 2400 desktop as configured for $499 - $100 rebate = $399 with free shipping.

P4-2.53GHz, 256MB, 40GB, 48x CDRW, 16x DVD-ROM, XP Home
17" E773c Monitor, 10/100 + 56k, Integrated A/V, Stereo Speakers