Two thoughts:

Sabrina on Nineth and 43rd -- really excellent small contemporary American restaurant, modest prices, if you stay away from the specials.

Bricco on 56th Street. (I posted details about this restaurant recently on this board, so if you do a search you should be able to find it.) Good Italian restaurant. If you stick to the pastas you can easily eat for under $80 for two. Attentive waiters and an upscale atmosphere.

You can also walk up Nineth Avenue -- there are lots of reasonably priced restaurants from 42nd Street up to 57th Street, most of which don't even take reservations.

I like Dervish (Turkish food) at 146 W. 47th St. (bet. 6th & 7th Aves.). It has a $20 prix fix until 8pm. Judson Grill is pricier but very good.

Try Federico's. They have a website: http://federicosnyc.com/media/websitefedericos.html
Their priced fix menu (3 course) is $22.95 and I read it is romantic and not so noisy with a piano bar playing. We are doing that when we go in a month. It is on 50th st near the Gershwin Theatre (Wicked)