The drinks on RC are quite expensive if you ae a drinker, the soft drinks you have to pay for but on boarding the ship you can buy a pre-pay sticker which they will stick on your room card, it is about $30 depending on the length of your cruise and what ship you are on and this entitles you to free unlimited drinks throughout the duration of your cruise, I think it is well worth it as when the weather is very hot your drink can get very warm so you can have another one and so on and so on.
They're not as expensive as you'd think actually. Copy and paste this link into your browser and you'll see a price list of drinks on board the Serenade of the Seas from 2005. Things have probably gone up a bit since then, but not too much.
Just got back 2day from NAVIGATOR and drinks are all priced in dollars and at current rate that makes very reasonable JUST LAST NIGHT !! 3 VAT AND 1 ORANGE JUICE COST 21.25 usd ABOUT £10.60 . FREE COLD DRINKS ALL DAY LONG PUNCH LEMONADE etc free ice cream HELP YOURSELVE , have fun WE DID.