When it comes to dining deals, Boston is figuratively your oyster. Join Rialto every Monday evening for $1 Island Creek oysters (pictured). The oyster-fest begins at 5:30 and ends when the supply runs out. Looking for bivalves in the South End? 28 Degrees serves up $1 oysters every Thursday night from 5-8 p.m. Still can’t get enough? For just $1 each at Marliave, slurp up four different types of local oysters and clams from 4-6 p.m. and 9-10 p.m. daily.