This holiday season 2018 at the U.S. website and dealers here, the price of the top of the line Powerbot 9350 is reduced to the same $799 as the 9250. The 9350 includes the "select-a-room" persistent mapping omitted in the 9250, otherwise very similar. So why would anyone buy the lower model? Could be a matter of availability in different places.
The lowest end $7040 is reduced to $289, not unusual for a bottom line model.