$7 for Guacamole - This is high for Phoenix. If you look at the menu for a mexican place just off of Rodeo in Beverly Hills a scoop of Guacamole about half of what you will get at Paz is $3.95 (http://www.fridarestaurant.com/beverlyhills/menu/dinnermenu.pdf).
Common logic would dictate that the guacamole would be cheaper in Phoenix than Beverly Hills.
The tacos were ok, the porkbelly was a little old and basically just placed on a tortilla. They might be better served by purchasing a package of trader joe's pre-marinaded carne asada as well.
The hero of the night was the green salsa. That was pretty good. Your work is cut out for you to compete with Crescent Ballroom and La Santisma.
Perhaps the best strategy would be to forgo the waiter service and just order at the counter. That would drive down the costs of a wait staff.