I would say its a combination of things. Havertown is traditionally more blue collar, the homes are smaller, the lots are smaller and supposedly the schools on one side of town are much better than the other...there is a "wrong side of the tracks" there.

Haverford is considered the Main Line which is the most affluent area around here...so there is the "snob" factor driving housing prices, and I would guess the neighbors would be more upper class than middle, the homes would be a tad larger with more land around them...