This was one of the stops on the UYE: Twoonie and Loonie Crawl.
$1.25 gets you a taquito (literally "little taco"): your choice of filling with garnish on a single-ply corn tortilla. 74 cents more gets you a full-sized taco on two tortillas.
Choose from an array of meaty fillings lathered in stewy juices like pork in chipotle sauce, chicken in mole, or chicken in pepitas (pumpkin-seed puree). They also serve tostados and tortas (Mexican sub sandwiches).
I recommend the cochinita pibil (saucy pork) with pico de gallo and some hot green salsa. Wash it down with a Mexican juice then take all the money you saved and [WARNING: BAD PUN ALERT!] go nuts at the bulk food market around the corner.