I stayed at the Penn Station Howard Johnsons (Don't remember the exact address, but it was basically right across the street from Madison Square Garden and Penn Station - easy enough to find online). The room was ~ $110, which was pretty reasonable considering it's NYC. The location was pretty convenient in terms of traveling to the school on the subway, and it was a fun area to hang out the night before, so I was pretty satisfied. Definitely give it a look. Good luck at the interview!
If you're not averse to staying with students, ask the admissions office to set you up with a host. They keep a few mattresses on hand for visiting interviewees as well.