Donna
I have been to New York twice and I agree with what Julia has said. Also please take inboard there is so much to do and see, I don't know what you intend to do or if you have free time but here are a few things I have done and can recommend. Most of these do cost, some you will get prices online.
9/11 Museum
Statue of liberty both of these I arranged and paid for online in the UK before I went..saved in queuing up and paying on the day and you are fast tracked, well worth doing.
Horse drawn buggy ride around Central Park, myself and 3 other ladies split the cost of this, they are by the entrance do ASK price before you get on.
Lots of museums some are free but they do like a donation if you can. I went to a very interesting Jewish Museum.
If you have time queue for the cheap theatre tickets well worth doing some great shows to see.
There is a revolving restaurant, which I had a meal at the views are amazing.
I did do helicopter flight over New York well worth doing again amazing views,
A trip to Macy's is well worth doing.
So depending on what it is you want to do, and I would really recommend you doing all you can, this will add to the amount of money you might need to take.
Have a great time there is so much to do and see you will have a great time
Cindy