ebay (via GetItDigital) has the Canon 5DS for $3,199.99 (reg. $3,699.99). Check it out here on ebay.
Note: This is labeled as a gray market item and, therefore, won’t include a US warranty card. At the time of this post, ebay seller GetItDigital has a positive feedback rating of 99.6% and offers its own 1-year warranty with the camera.