Assuming you are working with an agent representing you and not the seller, I would have him/her guide you. Many factors affect (effect?) the ratio between listing price and the final selling price of a property, and a local agent working for YOUR best interests will have more info about the building, the community and the general amenities of the area. Best of luck in your endeavor.
are you interested in making an offer? or is this an auction sale? if it's an auction, they instructions are usually provided by the county. If you are interested in a particular coop, you would need an agent to make an offer, and represent you as the buyer. Email or call me, i can help you. I am experienced in the area.