What would you offer for this dslr?

Nikon D3000 w/ kit lense & 55-200 lense.
Good working condition. Used as a back up.
Roughly, what would you offer(cash price) to the person selling it?

$550-650

No one will buy it. Cameras and technology are based around being new and cool. The only bottom feeders (which is not a negative term here) that will buy it are looking for low price. If all of them are $500. You will only sell if you are $475.

The D3000 is the basic entry-level Nikon and it's discontinued, you can get the new D3100 kit AND the 55-200 for about $650 brand new online if you look around. I would offer no more than $400 if it's in okay condition with the kit and 55-200 lenses, but no more than $500 if they're spotless and come with accessories. I would start the offer at $350-$400 telling the guy what I just told you.