I'm afraid you'd need to be much more specific as to the area in New York City you're interested in and the type of property. And even when you narrow it down to that point, you'll find there's no real "average" price. Home valuations here in New York can literally change from one block to the next.
Your best bet: find a great local Realtor in the area you wish to buy; show you're a serious buyer and shop 'til you drop!
PowerHouse Solutions, Inc.
185 Great Neck Rd, Suite 240
Great Neck NY 11021
Licensed Mortgage Banker â€“ NYS Dept. of Financial Services