I get to NYC about every other month during the last several years. This kind of pricing is not unusual. As someone suggested, the chain hotels near EWR are typically much less. However, I found just flying into EWR and going into Manhattan to be inconvenient as compared to taking Amtrak from DC, so I reject that idea. Instead, look at the many independent / boutique hotels in NYC. You can often get a rate somewhat lower than in the chains. When Hampton Inn or Courtyard is $400/night, an independent might be in the high 200s (all before taxes).