Grandaisy Bakery (on West 72, right next to Gray's Papaya between Bway and Columbus) has wonderful, Roman style (i.e. thing) pizza with delicious toppings for $2-3. Had the cauliflower topped pizza a few weeks ago and it was glorious.
They have other sandwiches as well....
There's a nice little bakery on W. 74th Street in the Ansonia building, on south side of 74th across from Fairway (sorry--name escapes me--think it starts with an "M"). In addition to baked items, they have have light fare (sandwiches, etc) , that might do well for lunch....
It's take out.