Not today, but three days ago.
I bought a uses Dell Precision M6800, with new battery, 240W power brick, 32GB ram, new 512SSD, new 1TB SSD and backlit keyboard.
The battery was new in 2015.
The power supply is 180W.
I checked expressly for a model with backlit keyboard.
Here is the picture of the backlit keyboard:
And here's a video that shows how one can't see it when in broad light.
https://youtu.be/3GO4Wpbm8QI?feature=sharedNow, the seller told me it will change the battery and the power supply and 'we will find a solution for the keyboard'.