On two trips to the East Coast each of the past two winters [mid-January to early February], I've tacked on a New York excursion. Last year, I stayed at the Residence Inn New York Manhattan/Times Square at 1033 Avenue of the Americas [6th Ave] for several days. It was very adequate and typical of New York hotels (don't expect a lot of space to congregate outside of the actual public spaces). This year, I stayed at the SpringHill Suties New York Midtown Manhattan/Fifth Avenue at 25 West 37th St (next door to the Fairfield Inn & Suites New York Midtown Manhattan/Fifth Avenue) and even extended my stay for a night or two after my arrival at still decent rates. In each case, the rate per night was cheaper [$150 or less] than what I paid in other cities on my trip (last year in Boston, this year in Atlanta). The rooms in each hotel were about half the size of their counterparts in other places (again typical of New York), but very adequate for a solo traveler. The staff at each place was very pleasant and accommodating---more so than many of my fellow travelers. Both places are very near Bryant Park (with a brand new Whole Foods Market open this year, very convenient for snacks and some locally-sourced treats). And of course, blocks away from NYP.
Rates fluctuate wildly; April is somewhat of a shoulder month---past any winter doldrums, but not yet quite summer tourist season. It's also still in the Spring Break time frame, when there are many tours that come to New York, and thus drive up rates a bit. Be sure to check back frequently as to options and rebook as often as necessary.
Also, hotels have been getting in on the Black Friday madness with major chains offering system-wide discounts for future bookings made in the week after Thanksgiving. It's worth checking out around this time frame just in case there are other properties doing the same type of discount. As is often the standard advice around here, avoid prepaid reservations which don't allow for cancellations or changes after booking and I would avoid third-party or blind booking sites to make reservations at places which already have an in-house reservation system or affiliation.