Canon refugee needs advice....

I'm not sure why anyone would suggest the 24-70 2.8 since you're asking for best PRICE and performance.

The 24-120 f4 is the best price/performance FX mid-range zoom or the "beast" (used) which is the 28-70 f2.8 if you're not familiar.  Either are very close to the 24-70 2.8 - the 24-120 is VERY sharp wide open and no lesser quality than the 24-70 2.8.  It's solid, sharp, and has a gold ring - sometimes I think "lesser quality" is thrown out there to somehow explain price difference - not true.  The price difference is f2.8 vs. f4 not quality.  Much like the 24-105 f4 from Canon - which is every bit as sharp wide open as any 2.8 lens - just not..well...2.8.  

In 3rd party lenses you can try the Tamron 28-75 2.8 which is easily the best value for an FX mid-range zoom (owned 2 over the years - very pleased).  The newer Tamron 24-70 2.8 with their version of VR is in the 24-120 price range but gives you 2.8 - very popular lens not quite up to par with the Nikon 24-70 2.8.

Oh, and you probably should ignore any DX lens recommendations (16-85) - just doesn't make any sense to buy FX and slap a DX on it when there's plenty of great FX glass at just about any price point.

Hope this helps,

Joe