Certain cruises do other a drinks package but not heard of this on Princess, but someone may correct this statement. It depends on your level of accommodation you have booked the brochure should tell you or go onto the cruise website and check it out there. The bar prices are the same in all lounges and if you were say having a can of coke out the minibar if one where available it will normally be the same price at the pool bar or any other bar on the ship. We go for gin/tonic and caribbean rum and lemonade and on most ships that comes in around £7, but the measures are normally bigger and you pay 15% on top for service. Check out the prices in the bar and watch which ones you choose, if you did ask for a gin they will unlikely serve you the cheapest, so ask specifically when you order. Finally you must remember you will probaly pay less on the ship than you would in a 4 star hotel which likely your ship will be 4 or 5 star, it certainly won't be the price it is in your local back home.