Your burning daylight!
Call a cruise specialist agent if possible. You are not going to pay any more using an agent than you will by booking directly with the cruise line. For today's deals (and for most bookings - but not all Neil!) the price offered by RCCL directly will be the same as any agency can get the cruise for. Remember, an agent is an advocate. The person on the other end of the phone at RCCL is an RCCL employee - but they work for commissions just like a "real" travel agent.
No matter who you book with, all you should pay today is a deposit - and on today that deposit is supposed to be 50% less than normal.