Haven’t had enough margaritas for one week? Head to Mercadito Grove (100 Seventh Avenue, at Grove Street, 212-647-0830), where you can get a traditional margarita for $5, a margarita with fresh fruit for $6, and red or white sangria for $5. Cut your tequila with the restaurant’s signature guacamole, which runs from $5 to $6. The happy-hour special happens Monday through Friday from 4 to 6:30 p.m.