How much money should I take?

So I'm visiting new York in month (can't wait!) and I'm wondering how much money I should take.

I'm going there for 5 days. I have a couple of excursions booked that I've already paid for and I'm not planning on any big shopping trips. I also know I have to pay city tax so I was thinking about $500 for food, a couple of souvenirs and travel.

Yay or nay?