Scenario: You're with two friends watching basketball at a Annapolis bar, and after steadily tipping $1--$2 per drink, the bartender buys you a round. How Much To Tip--And Why: $12. The fabled buyback should be rewarded, generally with an amount about the price of a round of drinks. (Don't expect buybacks in touristy areas.) Different bartenders have different rules for when they give customers freebies--one for every third or fourth round is common. Tip more if the buybacks come more frequently, or if you're given appetizers or shots on the house.