Last summer drinks were (I think) $6.95 and a refill was $5.95.  Yes - they will do a refill so keep your glasses handy.  I have not ever thought they were watered down either.  Keep a watch for specials - the drink of the day and such.  There is often a drink special at certain times in the casino.  Cold beer is also great when you are out on deck in the sun and you can often find special "beer in a bucket" and I think it was like 4 beers for $12 or something along those lines. 

 If youre a big drinker..id say skip the mixed drink specials they have and go for just shots.  They really aren't too bad compared to state side bar prices..and im sure they'd be cheaper than the ones in nyc.  Gf n I thought the mixed drinks were watered down and are a waste, unless u just wanna get it for the souvenior purposes.  We bought one of their special drinks that came with a coconut monkey thing for $18 or so and it was a complete waste.  The monkey was cute but not $18 cute.

Or you become good friends or just friendly with one of the bartenders and they mix youre drink in front of u with a lil extra "splash".  

Hope that helps.