Why did you decide to move up to the 1D?
Better build and sealing, interchangeable focusing screens, integrated grip (battery grips are always on my current bodies), more customization, features like AF point linked spot metering, etc. The faster frame rate and better metering are a nice bonus. I'm not fussed about 18 MP, it's enough for my FF shooting needs (but I am keeping my 7D for birds/wildlife). About 10-15% of my shooting is with the 7D, the rest with the 5DII - thus, 1D X and 7D makes more sense for me than 5DIII and 1DIV.
Craigslist is lousy with 5D2s these days. Lots of Nikons as well. I think everyone is having the same idea. It's a buyer's market as far as used 5D2s go.
That's ok. Fortunately, I don't need the funds for the 1D X. I feel like I've gotten my money's worth from the 5DII, regardless.