Hi BksMsCaramel & welcome to Yorkie Talk! You'll find a wealth of information here on YT about this beautiful breed. I also live in the NYC area, and I'll tell you now you'll be hard pressed to find a yorkie for the price range you are searching for in the immediate Tri-State area. Especially one with a health guarantee that the puppy is in good health and have no defects or have been inbred, etc as you've said. There are many seasoned and reputable breeders here at YT, that I know once I am ready for another I would go to them for a puppy. These breeders have done extensive research and put a lotta blood, sweat & tears into their programs; and even though I know many of them still strive to improve their lines, I believe them to be soild & ethical breeders.
Woah, little off topic there!!!~ In short I think for a quality healthy puppy especially in the NY area you'll have to look to spend around $1000 for a puppy.
Good luck in your search!!!~