I would like to say around 800-850 pounds fully loaded with the spare tire which is around the same or a little over what some guys gfc/vagabond fully loaded set ups are.
I know for sure that the tent is 190 pounds because I was able to put that on my scale and really just guessing the box is around 600-650 pounds with the drawer, spare and fridge drop slide
and I also want to say my flatbed is somewhere around the stock weight of the old bed maybe a little more but I decided to use steel mounts in between the frame and the actual aluminum bed and somewhat over engineered it so if you were to build/buy one it wouldn't make any weight difference.
If you are to fully hard-mount it and build just a steel and/or aluminum frame only vs the whole flatbed to hold it that would shed some weight off it also.