Kelly, the 400 we have is the f/2.8 version and yes it's a bank breaker. We sold a ton of stuff to get this lens...think our house, one of our cars, a barn worth of collectables ....etc!
I'm not sure if I have a list of our entire arsenal except for the one that I put together for our insurance company. But I will say that it takes up the entire back seat of our truck. We actually took the back seat of our truck out and I built a custom box that is lockable and holds 3 backpacks worth of gear, a few smaller camera cases and a couple of tripods and monopods. Basically a life savings carried in the back seat of a diesel truck
This was one day while I was cleaning the gear and had it all out on the concrete
Here is a shot of Cindy with the 400 f/2.8 Its a tad bigger than the 400 f/4
and ALOT heavier!! 11.8 lbs to be exact