In todays NYT Arron Kessler has a generally very positive piece on Autopilot that states that the update costs $2500. I have no idea where this came from and there's no way I found to let him know it's wrong.
http://www.nytimes.com/2015/10/16/automobiles/tesla-adds-high-speed-autonomous-driving-to-its-bag-of-tricks.html
http://www.nytimes.com/2015/10/16/automobiles/tesla-adds-high-speed-autonomous-driving-to-its-bag-of-tricks.html