Upload & Sell: On
My high-school running coach had a simple saying: "You play... you pay."
Don't do anything where you can't afford the consequences, in any sense of the word. Know where your limits are. Then, do the right thing. That is sometimes buying a new camera. More often, it's not.
Now, forget the past... including five minutes ago. From this point forward, what's the best decision: keep the D600, or return it and get a cheaper camera, or what?