I can't picture a trip to NY for a "few days" including airfare, hotel, transportation and food for under 5 K
Drive (if you're close enough); then if you happen to find speakers you really like, you can take them back with you (and save on shipping).
Don't stay in Manhattan. NJ, maybe. Look for unpopular dates and for deals. Even in Manhattan, you could stay in a Pod for ~ $120/night (incl. taxes & fees).
Eat street food (or bring something along). You should be able to get a panful of rice rolls in Chinatown for < $5. Big Tray Chicken at Spicy Village (Chinatown) < $20, enough for 2.
I would think you could have an enjoyable experience for about $250/day. Frugal, but not spartan.