Going out for a pizza is probably the cheapest way to eat out in Livorno (and Italy). It is the favourite choice for families and groups of friends, including teenagers' birthday celebrations. In fact, some pizzerias specialise in large groups to meet this demand. These places are usually very efficient, but can get very noisy!
Many pizzerias also serve ordinary meals and you can combine a starter, a pasta dish or anything else, with your pizza. In Livorno, some pizzerias also make torta di ceci, served either with or without bread. Ask for them to bring 'un etto' (100g) if you just want to try it.