According to a Netherlands-based retailer listing, spotted by an eagle-eyed Reddit user, Lumia 950 XL pre-orders may include the Display Dock accessory as a bonus. The listing was spotted on Belsimpel.nl, and contains the following line in the description (translated)
"Pre-Order the Microsoft Lumia 950 Xl between October 9 and November 29, 2015 at Belsimpel.nl and receive 500 Microsoft HD Display Dock completely free!"
As we reported earlier today, the Display Dock will run $99 separately, so this would be a pretty great deal if it expands to other retailers as well. Unfortunately, it looks like this bundle looks to be only for the Lumia 950 XL, not the Lumia 950.
For those out of the loop, the Display Dock enabled Continuum on with Windows 10 Mobile devices, essentially allowing you to use your phone as a Windows 10 PC when connected to a monitor, mouse, and keyboard through the dock.