I think it is pretty standard, I am not in the city or near Boston, so maybe in Boston it would be higher, I don't know.
but I think its pretty comparable,
I only work part time, don't take any health insurance, my schedule is flexible, ( I make it ), and they pay my malpractice insurance and for ceu's
I think you will find you will not be getting a huge pay increase when you move to the NP role. maybe even a decrease depending on where you work and how long you have been there.
one of my good friends is an RN, and is at the top of the pay scale where she works, she has been there over 20 years i think and she makes $50 an hour :)