Students aren't allowed to sublease dorm rooms. The dorms will not allow access to someone who is not a student. You have to have NYU ID etc. Each dorm has security and neither administration nor other students want non-students in the building (the only time this happens in the summer when interns are able to rent in certain dorms etc). What in the world gave you the idea to rent a dorm room? You need to stay in a hotel or airbnb. You have a small budget and that's going to be tough, I don't think anyone is going to accept $400 for 2 weeks of housing in NYC. It's nice you want to visit NYC but it sounds like you didn't think this through very well and you should save up more money and visit in the summer or a year from now whenever you have more money.