you are better off going thru an agent. you will get the same price and alot of times they will have discount coupons for you to use. when i booked our cruise we rec'd a coupon from rccl a couple of weeks later. took it to our agent she place a call to rccl and they took the coupon amount off. then to our surprise when went to pay the balance off we rec'd another discount coupon. we got a total of $100.00 off. then if you have trouble with reservation let your agent solve the problem(s).
hope this helps you. we use our local aaa office for both of our cruises and it has been a real pleasure working with them.