The "Pizza al Taglio" at new Soho spot Piazza 17 is a pretty good deal. This square slice (Prosciutto, Eggplant & Mozzarella) cost $3, and it's substantial enough to be lunch.
Don't know if its even on the menu, but theres an $8+tx lunch special: any 2 slices & any soda. As for the pizza: its all about the toppings. If you don't like yr plain slice, don't say ya didn't know