"Radnor" can be in Upper Merion or Radnor Township, while "Villanova" can be in Radnor or Lower Merion Township. Generally, homes in Townships with perceived excellent schools will be higher priced than the same home in a Township where the schools are not as highly regarded. Taxes are lower in Upper Merion because the large retail businesses there (King of Prussia Mall) generate tax revenues for that Tonwship. Taxes are high in Radnor because the schools are well-funded.
As Nick has said, all real estate is local, even from hosues to house, so I am not sure if the answer will be helpful or not.