Gabriel's on 60th between Broadway and 9th avenue would be a good choice. Very good Italian and should fit the budget nicely.
If not, there are 4-5 restaurants across the street from Lincoln Center that fit the price range, but I'm not sure about the cuisine.
Edit: Gabriel's is about 5 blocks from Lincoln Center. If taking the subway, go on the 7 from Grand Central to Port Authority and one stop north on the A train (Columbus Circle). It's on the north side of the Time Warner Center.