Hello. If you booked directly with RCCL, I would call and ask them about it. I got a $700 refund on my Freedom cruise we took this june, I had booked directly with them. I called and asked if I could get a refund. They credited my credit card $700, our cruise was for 3 people.
I also got a $300 refund on our Princess cruise. I had caught that the price dropped, before my travel agent. Because we had booked with a TA, my TA had to request the refund.
So, it does literally pay to check the fares after you book. I have also gotten travel vouchers good for the difference of my airline flights that have decreased. That only has happened once, on America West, I remember it was a couple hundred dollars. The voucher was for the difference, and if I remember correctly, it expired in 1 year. I could only use the voucher to book at the airline terminal. It was worth a trip to the airport I thought.
Anyways, it never hurts to ask for a credit/refund if the price drops. You never know!