They only sell toppings on whole pies (including the small pie). The exception is peperoni, but i didn't want a peperoni slice, so had to go next door and get a sandwich (bleh). Its a shame because I've been getting their spinach slices for 2 years now.
Just posting so that people don't go all the way there for a slice with a topping, and find that they can't buy it.
It isn't great pizza or anything, but it is decent (and I like it better than Mario's). Roma's pizza was bit better when I first moved here, but even then it wasn't all that. If I had a car, I'd go to the Italian Store.