Ballo Blanco is fantastic! Located within the hip Clarendon Hotel near downtown Phoenix, this is one of the best places for brunch / lunch in the $10 - $12 range. Tacos range from $2 - $3 each with 2-3 composing an adequate amount of food for an entree. The cochinita (pork) and Ahi (eco-friendly and the current Market Selection) tacos are my favorite but the carne asada is also good if you're in the mood for some beef instead. The Pico Rico Burger and Naco Torta are also fantastic if you're feeling like a sandwich, the Naco being another one of my favorites. The coffee is great, the fries are a must for $3 and I while I've yet to order the Chicharron de Queso for an appetizer it looks amazing!
The service might not be 5-stars depending on the day but they can get very busy and at the least they are always nice. If you haven't already been to the Clarendon Hotel itself it's very cool and has a beautiful pool that's open to the public on certain days as well!