The duplex remains on the market, now priced at $695,000.

On Riverside Drive, a large one-bedroom offered an eat-in kitchen, a small office and a wraparound terrace with three exposures. The asking price was $695,000, with maintenance of nearly $4,000. “The maintenance was way too high, and I think that’s what probably worried every potential buyer,” Mr. Chen said.

The Upper West Side was yielding no viable options, so he turned his attention to Brooklyn, where he thought he would also be glad to live, as long as he had a reasonable commute to his Midtown office.

On the edge of Downtown Brooklyn, near Brooklyn Heights, he found a one-bedroom in a 13-story co-op building that had been constructed in 1928 by St. John’s College as its main downtown campus building. There was no outdoor space, but there was a common roof deck.

The listing photos were beautiful, showing an L-shaped space with huge windows, a corner bedroom and stairs leading to a lofted sleeping space above the kitchen. The ceilings were 14 feet high. The listing price was $970,000, with maintenance of a little over $1,300.

Mr. Chen’s first question was about the ceiling height in the loft. It was six and a half feet. “That is a bonus, because you can stand up in that loft,” he said.

At the mobbed open house — he didn’t want to leave this one, either — he instantly knew this was the place.