I'm delighted that you've found it to be a worthwhile venture....hopefully the buying public will agree and will make this publishing effort a success to the point where the authors might consider an update including a more comprehensive accompanying volume of etymological facts rather than merely the short blurbs that they include on the back of the maps in this edition. It's a compelling concept which tends to raise passionate curiosities in many people. I certainly wouldn't mind paying extra for a larger, more definitive reference work in a similar atlas format.
Do you have a direct link to sales information? When I tried to pull up the source, it thought and thought and thought until I had to go change a diaper.