Find the closest amateur radio club to you in New York and contact them. Someone in the club is likely to either have one they'd be willing to part with or know where you might find one, where to potentially find classifieds listings for things like that locally, etc.
You could also look for hackerspace / makerspace type places and ask the members there.
For an area the size of New York, I'm amazed at how few total listings there are on places like Craigslist, Locanto, Oodle, etc. It seems to be just used for housing! Wow. Here in Calgary, AB, where we only have about 1.2 million people, there are currently more than 414,000 ads on Kijiji (a popular Canadian free classifieds website) alone, in every imaginable category. Only 8 oscilloscopes listed right now, and no bargains but I can't believe there aren't more local classifieds of some kind in New York.
I stumbled across a Kijiji listing a few years ago for an estate sale of an electronics guy who was into TVs and radios and stuff with some interesting pictures of piles of gear. Even though I had never gone to an estate sale before, I was intrigued and so I stopped by later in the afternoon on the day of the sale while I was out and about anyway.
WOW, I should have gone earlier! There were only a couple people left when I got there and I was the last person to buy anything. They were selling every unit there or box of parts for $20 each for large items, $10 for small items. I got all sorts of neat stuff! An old Precision E200 signal generator, a Heathkit visual alignment rig, RF probes, a Fluke 80K-40 high voltage probe, a bunch of other smaller stuff, some books ($1 each, IIRC... Good ones, like Peter Keller's history of CRTs book,) almost bought a vectorscope (in hindsight, I wish I had grabbed it!) I spent all the cash I had on me!
INCREDIBLE deals. They knew the stuff could potentially be worth much more but just basically wanted it all gone, even if people were just going to turn around and sell it on eBay or something. Not me! I wanted to USE this stuff!
Part of the reason I went was to try to get one of the many scopes pictured in the original ad, but of course those were all long gone, since they had been selling them for $20 each! All sorts of radios, HAM gear, etc.. Oh, my... Had I known they were all going to be $20, I would have been there first thing in the morning!!
I stuck around and talked to the guy for a while (a family member of the gentleman who had died) and helped him out as he was finishing up, taking down tables, locking up the place, etc. and he said I'd be welcome to come by the next afternoon since he would be there cleaning more stuff out of the house anyway. I called a fellow electronics friend and we went over the next afternoon. The guy had found even more electronic goodies in the house, which I bought, including a Sencore CR70 CRT tester, (SUPER nice score! A 1993 model with all the adapters and latest set-up book, my eyes almost popped out of my head when I saw the black case, I knew EXACTLY what it was!) a Sencore pattern generator, a Heathkit impedance bridge and all sorts of other goodies. I basically made a pile and we just settled on a price. My friend got boxes of rheostats and pots and a whole bunch of other stuff that I can't remember. I was too fixated on my growing pile!
My point is, there are lots of places where you can find excellent bargains on stuff like this, so don't give up too easily on your local area, you just need to do your homework, keep your eyes peeled and be patient!
Good luck!