Being a new comer to the New York City real estate scene, you should know that the vast majority of sales here involve two agents ("brokers" in local slang) -- one for the seller and one for the buyer.
There are a lot of reasons for this, the most important one bring that the listing agent is obligated, by law, to do his or her very best for the seller--not for you. Anything you let slip about your finances, for example, can and probably will be used to extract more money from you. Good brokers take courses, including role playing and theory, on how to win in negotiations.
So even for second or third time buyers, it's routine in NYC apartment sales for there to be two brokers. The brokerages agree to share the seller's agent's commission for the benefit of all. So, if you don't work with a buyer's agent, then you are paying for a service you're not getting.
If I were your buyer's broker I would pull records on the history of the building and on the particular apartment, and I would help you negotiate the best possible outcome for you given all the info we can get our hands on. I own an apartment on the Upper East Side, I know it well, so if I can help, Matt, please let me know.
Licensed Real Estate Salesperson
New York, NY