It can be an absolute rip-off if somebody opts to become a "tourist".Stay away from San Marco, choose light lunch from bacaro's, eat where locals eat. You can get a glass of wine for 2.50 Euros. We went to Harry's Bar and got drunk with the bill (almost 50Eu for a margarita and bloody mary). Avoid going to Venice in summer! The canal water stinks and it is too crowded.