If you're going to Paris before or after Italy this looks like a good deal, especially since Rick recommends this company so highly. It appears that they are launching Walks of France and are running their first tours in Paris. I'll also post on the France forum.
Edit: Oops, my screwup! Didn't realize this was a discount for me via email, not a blanket discount like WOI does at certain times of the year. In any case, their new Paris tours look great; they start in March.