Budget US$2,500 Used D3, D600 or save for D800????

Hi Guys

I Currently Own D5100,D80 and D2XS Bodies. Nikon 17-55 2.8, 70-200 VR1 2.8, Sigma 10-20, Nikon 18-200( I dont use it), 50 1.8, 2 SB800, 2 SB600, 1 SB900 .Im getting rid of the D80.

The Problem is this, I Work Taking Pics at Night life Events and I love the D2Xs body, Feel, Viewfinder, Battery...... but I hate the low Dynamic Range and Hi Noise. I Bought the Small D5100 and With the 17-55 2.8 It is Miles ahead of the D2Xs in terms of noise and dynamic Range. I need to Upgrade.

My budget is $2500 Should I

Buy D600 $2199

Save for D800 $2999

or Buy Used D3 ~$2199

I Don't need Video, my Prints are ok with 12MPX, I don't need 36MPX. I like the Robustness of a Pro D2 D3 body. What would you Guys Recommend??