Rich towns have low taxes?

ive noticed that new wealthier towns in nj have a lower property tax ratio compared to middle class or older wealthy neighborhoods. One big question is why a town such as "new money" old tappan with barley any commercial development and mostly new housing has lower property taxes than a wealthy "old money" town such as montclair, englewood or south orange, given those towns have a large commercial district which should lower the overall town expenses? right?, which in turn reduce property taxes. newer towns such as old tappan or alpine have all new construction housing, dont new houses have higher property taxes than older ones? its a common guideline like when building an addition to a home, homeowners like to save most of the existing structure, as the building will be listed technically as an older home and have a lower tax bill. after asking my friend he said its a conspiracy theory that the "new" towns which have mostly a white homogeneous population have back room deals with the state to increase taxing to more diverse, intellectual and liberal "old" towns such as montclair. plz i want actual answers no PC b.s.!!