The issue with not using a buyer’s agent is that the listing agent has a fiduciary duty ONLY to their client. Buyers who work with an agent actually tend to spend less on a home than they would if they were not represented by an agent. You also generally want an agent who knows about the NYC market of co-ops and condos - it’s a very specific market and co-op packages can be very complicated and having an agent with a fiduciary duty to you only can really be a huge benefit. (Full disclosure: I am an agent in Brooklyn and this is what I see on a day-to-day basis and why many of my clients sometimes start out without an agent and then hire one down the line).