That's a damn good deal!
D4 is still very new. Like, have to put on order and wait new. It's $6000 for the body, new
The D3s is the upgraded version of the D3. It's readily available new and used. It's About $5000 new and $4000 used. Seen a couple for around $3000
D800 is also new and is $3000 new and the D800e is $3300.
I'd really like the D3s.