Hi susnd66, welcome to Cruise-Chat! The drinks are no more expensive than going to a nice club or restaurant. Normal mixed drinks run from $5-$7, call liquors are more. Beer $3 and up. Wine $6 and up. They do have specials like bucket 'o beer, buy 4 get 5, wine by the bottle (which you can recork and take to your room or have for your dinner the next evening), etc. Not buying the drinks in the souvineer glasses will save you money, too.
Congratulations on your up-coming cruise!