Start saving your pesos: A night at Tamayo, Larimer Square's upscale, modern Mexican cantina, could wind up costing you a pretty penny. Or leave work early, because hora feliz, Tamayo's version of happy hour, is one of the town's best bargains. From 5 to 7 p.m. Monday through Friday, Tamayo includes a free tequila shot with every margarita; there are also plates of complimentary botanas, traditional bite-sized appetizers, including awesome guacamole, tasty quesadillas Surtidas and delicious mahi-mahi ceviche. There are always fourteen margaritas to chose from, including Tamayo's signature drink, the top-shelf Margarita Oro ($8.95), made with Herradura Anejo, Cointreau, fresh fruit juices and a float of Grand Marnier. Served on the rocks with a salt rim and lime garnish, it goes down smoothly but has a definite kick. Ay, caramba!