You can try the foreclosed auctions at courthouses to see if you can get a deal.
This one is for Brooklyn. http://www.nycourts.gov/courts/2jd/kings/civil/foreclosuresales.shtml
http://www.hud.gov is for all over
I have seen 43000 for LI homes that were hit by Sandy. {I do not remember the link though.} I do not know what has been done to fortify the land in case another storm comes along either. I would not look at popular neighborhoods to invest and instead go with those that are up and coming like Ridgewood and Jamaica. I would also look at the Bronx because more metro north stations are going there. You can also get advice, financial assistance and find out what the current housing opportunities are at HPD. They do not seem to have a lot right now but you have to keep looking periodically. They may have a mailing list too.
http://www1.nyc.gov/nyc-resources/categories/housi...
Personally I do not want NY anymore. It is the most unfriendly place towards landlords in the US next to CA and MN. LI and Westchester taxes are just ridiculous. Orange county went up a bit too. This is why I went out of state. I got screwed but I still can eat and I am going to make a profit. Down south is way better and more landlord and tax friendly. The learning experience has helped me lay down better systems for my next deal.
If you do not want to go too far then consider PA or CT. They are 1.5-2hr far from NYC, you can access them by train or bus, and the prices of homes are lower. PA taxes are a lot less all around as well. You can hire a boots on the ground person, go to http://www.wegolook.com, hire a freelance photographer, or college student to take pictures of the houses that you are interested in inside and out. Do not trust what some of these realtors put up because they photoshop them. Have them video the neighborhood and block too. Biggerpockets, hubzu, and angieslist can give you recommendations on who to hire if you need a handyman or contractor. If you do a gut rehab you may want to use a local project manager to oversea the general contractor and his subs at least 3 days a week. Plus being that PA and CT are so close you can visit once a week.
If you decide to stay in NY you can get a multifamily with a basement or attic, you can decide to live there while you rent out the rest of the house. If not, you could also do an AirBnb, daycare, or rent for photoshoots and or studios if you pick a place that does not have a nosey home owners association. I even heard some people renting out their backyards for camping and weddings. Those ads that you see on certain buildings those landlords get rent for that too. Some fiber optic companies pay too but they normally want you to be in rural areas. Some people put homes in their parents name or have them cosign to pay less taxes.