Always enjoyed your photography and your second gallery above blows me away - looks like HCB to me
I haven't been paying attention to D7K used prices so I hadn't realized, but it makes sense that they are dropping since Nikon is giving new ones away over here for $893 dollars! Considering the D7000 remains Nikon's best DX camera that is one heck of a deal. I already considered the $1199 I paid a fantastic value, anyhow I am keeping my D7000 which believe me is not something I often say about my cameras.
Anyhow this year I sold my D300 72K actuation but I had to keep dropping price to make it stand out as there were other lower actuation ones for sale, I ended up getting $575 and I was doubly happy as it seemed to be going to a good home. I also sold my D700 by offering it at a good price and it sold for $1500, so my experience is price does motivate buyers.
Have you considered a longer path, which is keep the D7K and still get a D600? In my case a lot of "stuff" happened this year at work but the upshot was overtime which allowed me to get some gear earlier than I expected to. Perhaps there is some other avenue in your life (sales of other assets, generate additional income in some other way, or earn photography income) that will allow a different way of achieving your goal?
- if you need low-light then yes FX is wonderful, no doubt about it.
- shooting two cameras is way better than shooting one. I'm not saying I schlepp multiple bodies when I need to be nimble, but in many cases I don't need to be nimble and the second body is invaluable.
- some people don't like a mixed DX and FX kit and I applaud them as it tends to keep life simpler going all one way or the other. Myself I still find advantages in both.
Anyhow, love your photography and clearly I have to get that Silver EFEX and mash those pixels even half as good as you do!