Lunch in Rome

[elasticwaistband]

Hello,

I would love some recommendations for lunches for a family of 4 (moderately priced at 15 E ISH per person) in the following locations as we tour the city:

In Trastevere near Piazza Santa Maria;

Near the Colosseum (would love Asino D'Oro but they are closed most of August when we are there);

Near Piazza Venezia;

Near Spanish Steps.

Thnks so much.