Bob's bows are certainly at the top of the class, no doubt about that. The biggest difference in the prices is going to be in the woods and options that are on a particular bow. Bob makes some of the nicest looking bows anywhere, but he also makes some more basic models. If looks are important, things like limb veneers, two tone risers, stripes, checkered grips, snakeskins, take down models, etc, etc. all add to the cost.
Will the $1,000 bow shoot any different than the $700 bow? Other than differences in the limb core materials, I don't think you could tell the difference in how a basic bow shoots versus a really fancy one.