Upload & Sell: Off
My approach is that if you can afford it and you know you will enjoy it, then just do it. The resale value is great so worst case scenario you enjoy it for a while, resell later for most of what you paid. The bit you lose is payment for time enjoyed just like any other activity. Maybe the D800 is what gives you the greatest inspiration of your photographic life & you start taking even better pictures, someone notices, you get an opportunity then this takes you on a path that leads to bigger and better things.
On the other hand if buying one causes financial hardship or conflict with loved ones, then be content with what you have.
Me I'm leaning towards the D800E at the moment, as a primarily macro/nature photographer. It will be my first FF camera, currently I'm using a D7000 & mostly FX lenses. It's a fantastic hobby, makes me look at the world in a different way, takes me places I probably wouldnt have chosen to go to before I was a photographer. I've made new friends. My photography got me interested in other new activities. That led to other new friends, other new interests etc.
It's like my bike riding...I could ride any old bike but instead I ride an italian Pinarello bike, which is like the Ferrari/Maserati/Lambo etc of bicycles. It cost me a few thousand, is made of carbon fibre & titanium, looks absolutely gorgeous & is a joy to ride. The D800E will cost less than I spent on the Pinarello.... and I'm absolutely certain it will give me great pleasure and create new opportunities & experiences for me.
Sorry I'm probably not talking you out of it....(buy! buy! buy!) sorry...(buy! buy!)