Go to www.rccl.com
each week and price out the exact same cruise and stateroom catagory as the one you have reservations for. If you find the price lower, call RCCL, tell them what you have seen on their website, and you will receive an immediate no hassle refund. We just called and received over $360 back on our upcomming cruise.
However, it is only that easy if you booked directly with RCCL either by telphone or online.
If you booked with a travel agent, you will have to go through them.
A travel agent may or may not automatically do it for you.
We have found RCCL to have the same prices as travel agencies and see not reason not to book direct online with the cruise line.
Hope this helps !