Eating is ok.
I think it acomdations that are cray cray.
So premium will depend on where you want to live.
I've visited NYC a couple of time on pleasure and business. Never tried to do a formal comparison, so I'm no expert, but in my experience:
Restaurant food in Manhattan is crazy expensive, Street food and diners are reasonable in Manhattan as well as NJ, the Bronx and Queens
Rent & housing is insane in Manhattan and high in the nice sections of the boroughs. There are less expensive places to live, but they can be pretty tough neighbourhoods
Clothing, books, electronics is cheaper in NYC and in some case much cheaper.
Grocery store food is a little cheaper with a much larger selection available.
Gas is cheaper
There is a TON of lifestyle activities available, especially within an hour drive of the city.
Wheather can be harsh, more harsh than Toronto.
Google is good for this kind on info:
This site says 28.67% more (excluding rent):
http://www.numbeo.com/cost-of-livin...nto&country2=United+States&city2=New+York,+NY
This site says 40% more:
http://www.expatistan.com/cost-of-living/comparison/toronto/new-york-city