I swear the Guy Concordia metro station is stacked with great places to eat for cheap! Pizza Bella is an institution for all who pass through, especially Concordia students who need a quick bite before and after class.
$5 can set you up with a simple shishtaouk pita, or 2 slices of pizza. Maybe not the best you'll ever have but definately the best for the price you are paying. The pizza slices are dressed with generous amounts of toppings and are a decent size. Their wraps hold respectable meat-to-veg ratio, and are savoury on every bite.
Because this place is so popular they have a high turnover on pizza, meaning you are often eating freshly prepped food. A good feeling.