I will say that even though I highly recommend purchasing a refurb I also suggest spending the time to check it out thoroughly. I purchased a D700 refurb from Adorama and everything was perfect except it had one hot pixel in the upper right corner. Only way I could get it to show up with shooting high ISO at a white wall with a low shutter speed. It took some pixel peeping to even identify it. However, Adorama was great and I exchanged the camera.
I didn't bother to look at any profiles for glass .. but I'm sure you all know that the FX glass isn't cheap .. so if you don't already have something that works well with the D700 .. all those bucks on BING and BLING will go on more photo equipment .....
and I don't think it's a jump .... a jump is a D70 to a D300 ......... your changing formats from a DX to a FX ......
I've bought refurgs from Cameta .. they are wonderful folks to deal with .. I had an issue .. they sent the camera straight to NIKON for repair and NIKON returned it to me in a short amount of time ... ( one shot would drain battery on a D70 back in the day ).
refurbs .... every thing is refurbed these days .. warranteed and guaranteed .. it's the way to go if the difference is significant.
I have bought a refub d3 from my local camera store along with a 3 year total coverage warranty expect theft and been happy ever since..You couldn't tell the difference from a new one this..But it is a refurb from nikon..I would go for it to me it is better then new because it was sent back to nikon and set to factory specs..Mine only had 150 on the shutter...