There have been Jews living in Jerusalem for most of the past 3,000 years. The last time there were no Jews here was in the middle of the 13th century (when the Ramban, Nachmanides, arrived in town in 1267 he found only two Jewish men, brothers). Yet they've generally not been the wealthy Jews.
At any given moment in history prior to the 20th century, most Jews worldwide were poor, very poor, or hardly more than poor - as with most of humanity. There were however always some comfortable Jews, and a few extremely wealthy ones.
Not in Jerusalem, which had only poor Jews until the second quarter of the 20th century; truly wealthy Jews appeared in town for the first time only in the 1960s, and even then in small numbers.
Nowadays it's different. There are still many poor Jews in Jerusalem, especially the rank-and-file of the Haredi community and some of the old. Alongside them is a large middle class, a largish upper middle class - and some very rich people. (This is true about the Arabs, also, but they're not the focus of this post). Why, we've got a mayor, Nir Barkat, who has made hundreds of millions of $ in technology enterprises before turning to local politics.
In recent years - 10, 15 - there is a growing number of Jews who live elsewhere but own apartments in Jerusalem. They come here once or twice a year; some of them lodge their college-age kids in these large and expensive apartments for the year they spend in Israel; but most of the apartments stand empty most of the time.
The positive part of the story is that thousands of wealthy Jews feel a connection to Jerusalem strong enough to justify investing a million dollars or three in owning a piece of it. it wasn't that way a century ago, or half a century. The negative part is that thousands of apartments are empty, pushing up prices but generating scant economic or social activity.
The mayor has now decided to change this, if he can.