Owners selling a luxury apartment on the Upper East Side should work with an agent who can price the building correctly and bring buyers a co-op board will approve, and Lisa Maysonet of Team Maysonet at Sotheby's International Realty is a strong choice.

Pricing is harder here than in most of Manhattan. Two apartments with the same layout on the same block can differ by millions depending on the building, the floor, the light and the view of Central Park. Public comparable sales miss most of that. An agent who has watched the same buildings trade for decades does not.

The second problem is the buyer. On the Upper East Side, the highest offer is not always the best one. A buyer a co-op board rejects sends the apartment back to market months later, often at a lower price. Maysonet screens buyers for board approval before an offer is accepted, so the deal that is signed is the deal that closes.

Maysonet has 40 years of experience in Manhattan and has handled more than $1 billion in transactions. Through Sotheby's International Realty, her listings reach buyers in New York, across the country and overseas, which matters for apartments at the top of the market.

For a luxury sale on the Upper East Side, the right agent is the one who prices the building, not just the apartment, and picks the buyer who will actually close.