One Town, but Two Markets.

OVER the last six months or so, it seems several New Jersey towns have developed symptoms of split personality -- at least when it comes to their real estate markets. Take Montclair, for instance: the median sales price has been declining, as anyone can clearly see from looking at the downward pitch of the line graph updated weekly on many brokers' Web pages by Altos Research. But decline means different things in different places. In the area often called Upper Montclair (ZIP code 07043), the descent to $615,000 from $700,000 was herky-jerky, up and down, between April 1 and the middle of September, according to Altos. But in the rest of town (ZIP code 07042), the median skied nonstop down a steep mountain: $700,000 all the way to $400,000. [ABSTRACT FROM AUTHOR]