For a "specialty car" like a rare edition of a particular model, or a low production vehicle, KBB and edmonds are nearly worthless.
For an appliance like the Vibetrix or Fit, its usually pretty decent but it won't tell the whole story. Expand your search out about 200 miles and see what things are going for a little farther out. Go a year or two older, and newer, and a few more miles. See what is affecting the price the most. And remember, find your price for the vehicle, then offer lower to work your way up to that price.