We have just returned from our first cruise on sea princess and we bought coffee cards.they were excellent value at around 25 dollars each which gave you 15 lattes/cappuccinos,if you paid for them seperately you would only get 14 for the same money,and the drinks were really nice especially in the explorers bar on deck 5,have a nice cruise.
Get the coffee card. It's $25 for unlimited brewed coffees from the coffee bars and 15 specialty coffees such as espresso, lattes or cappuccinos, or hot chocolate.
One the card has been punched 15 times you lose it but check for more info on board.
The 15 punches refer to the espresso, lattes etc .