This is a weekly event that takes place on the grounds (outdoors) and the cafeteria (inside) of an elementary school in Manhattan. It has been there for many years. It's a nice show with a wide range of merchandise. I haven't attended in a few years, but I don't recall seeing any radio sellers in the past. My guess is that this could be the only radio seller.
Here is the official web site for the Grand Bazaar, NYC.
https://www.grandbazaarnyc.org