the soda card is $25.00 per person, unlimited fountain soda.
The only water that is free is tap water, which is pretty good. The water is purified on board, its not very cold, we keep a bottle of tap water in the stateroom fridge.
The price for an alcoholic drink is about the same as what you would pay at home at a good restaurant or bar. There are drink of the day specials, posted in your Princess Patter. There are buckets of beer available at the bar by the pool.
Haven't eaten at Sabatini's can't comment.