I also have the 5D IV and the 6D. The 6D is such a good camera, I would never get rid of it. It's a workhorse and I can bring it places I would not bring the 5D. But, new 6Ds go for about $1200, so I would ask half of that. Other than dropping the camera, the only important breakdownable things are the shutter wearing out and having to be replaced and the mirror function can fail, but they do and that's why I probably would not buy a used one, except maybe from an outfit like B&H who can check the "odometer" of the shutter and the condition of the mirror. If you're a hobbyist, obviously you don't need both cameras, but personally, I think it's worth more owning it than what you'd get selling it. JMHO