Hi, I haven't cruised with Royal Carribean before, but I have cruised many times with Carnival. The soda machines charged $1.50 per can of soda and it was almost $2.00 at the bars for a soda (they add taxes and tips on top of the soda fee), also a mixed drink was about $5.00.
on the Radiance in May a rum & coke was $4.10 including tax and tip. A large glass of domestic beer about a buck less and a can of pop $1.50. We bought a lot of liquor at the duty free shop on board and set up a bar in our room. It was very inexpensive that way. We would also buy a six pack of beer & cokes when in port. That is one reason we like RCL-their liberal liquor policy.