You can't buy one, but you can back what seems like a very interesting project: to help build a vehcile that could set an autonomous sailing world record. Eighteen days to go and they're at $30,000 towards a $80,000 goal.
From the Kickstarter listing.
Our boats have completed hundreds of hours of fully autonomous navigation and traversed hundreds of kilometers on the water.
We've proved a robust sailing algorithm. In the GPS trace below you can see the boat complete upwind tacking maneuvers without human control.
We've completed the Robotboat Mark VI design. We're going to build it like a surfboard; it will be incredibly strong and be capable of being rolled in waves indefinitely.