The West Village is one of the most expensive neighborhoods in the country. In around 2010, it was the most expensive zip code in the country.
That's due to a combination of: old buildings, very little new construction, extremely gentrified neighborhood, and NYU eating up all of the real estate in the neighborhood.
That said, the map is slightly mislabeled: what's labeled as the West Village is actually Greenwich Village, and the West Village is a subset of that. This map labels places as far east as Astor Place as the West Village, which is not correct.