Cheapest I've seen this one as well.
4000pa auction
LIDAR navigation
5200 mAh battery
Main difference between this and the L10 pro I posted earlier is the additional obstacle avoidance in the L10 pro. Few smaller differences including older firmware for the D9 max (according to support, this should be eventually updated) and inferior hardware which you probably won't notice.
$311.22 if you have eBay Plus and use FRIBLK22.
@JR63: I just got declined $650 for the D10 Plus.