I would add some extra thoughts here.

Long post but may give some useful information for those who care to read it.

First of all, EVERY booking place whether it is an online agency, a cruise-only agent, even a cruise-consolidator, they ALL need to make a profit after all they are not in it for charity. This is a given. The notion of booking thru an online agencies (there are indeed a TON of them) is always cheaper than going thru a real cruise-only agent is very misplaced.

In my experiences, using a cruise-only top agent has often beat the best prices I could find online, when all are added up, plus you get personal services which at time can become crucial.

We have over 20 cruises since 2005. (We had a few between 1990 and 1995 but stopped until 2005 to resume this mode of travel.) The first 2 cruises in 2005/2006 were booked thru "quotes" found from Cruisecompete or some site in that name where you put in your intended cruise(s) and got up to 3 quotes. Once I have found our current cruise agent via a cruisecritic poster's referral we have never used any other booking avenue. The NET cost I got generally matches or slightly better than what I could see from Cruises-n-more site or Crucon site. In fact cruises-n-more is my main source of finding what I wanted as I like its way of arranging things. I got Crucon's emails all the time but I dont like how they dont have all the details on their site and the only way to find out is to call, on their "special deals".

Here is why a cruise-only volume agent could get better incentives from cruiselines and then be able to pass to the customers. As a top volume agent, the agent often gets incentives in the form of group booking shipboard credits, free cabins, upgraded cabins, and miscellaneous shipboard niceties such as specialty restaurant / wine / photo whatever...
The agent can book you as among an invisible group if the sailing has group OBC incentives, or if there are free cabins the agent can put the cabins into the pool for sale but spread the value of the cabins to customers booked the same cruise, thus bring down the actual cost the customer would need to pay, for example. Different cruiselines have different mechanisms in its marketing and promotion / agent incentives of course. RCL works differently from CCL - while no agent can discount RCL corporations lines - Royal Caribbeans, Celebrity, Azamara, and such, agent could give you shipboard credits as a form of discount, not upfront, but it works out the same.

As for personal services, I can give you 2 examples why book thru a real person is better.

A few years ago we booked a Princess' South America cruise which I paid multiple times long before payments were due using as many as 6 credit cards to earn the sign up bonuses (back then the bonuses were much lower but the spend requirements also, in hundreds instead of in thousands.) We wanted to cancel the cruise by final payment due date (we had already paid almost in full except a few hundreds left) for a reason I forgot now.
The thing was, the final due date was on a Monday. We were going on a 5 day cruise on RCL's Navigator of the Sea on prior Saturday. Our cruise agent was on way to her own cruise to sail on Emerald Princess when I called her. I left urgent messages on her 1-800 and regular numbers on Friday. I got a call back that afternoon when she arrived FLL, that she would take care of it when she boarded Princess on Sunday. Not to worry. We decided to put the refund of the South America cruise to a Transatlantic cruise so we dont need to be bothered with the refunds going back to all the different CCs that 2 of them were already cancelled... She did all the works when she boarded Emerald Princess on Sunday. We later rebooked the Transatlantic when price went down a lot from when we changed.

Another example just happened a few weeks ago when we booked our upcoming 2 cruises sailing in October. We decided to sail Holland America's Noordam Transatlantic from Rome to Ft. Lauderdale on Oct 22. I wanted to add the last portion of the European/Africa portion to the Transatlantic, but realized it the per day cost on the Add-On was almost 40% HIGHER than the Transatlantic portion. So I checked other lines sailings and found 3 options - a NCL's Med 7 days, a RCL's Med 7 days and a RCL's Holy Lands 11 days - all can get us back in time to sail the HAL's Noordam. So I asked her quotes on all 3. She promptly gave me the NCL but told me to wait till next Monday for the RCL because both ships I eyed on, were on the Tuesday sales that opened on Monday for Crown and Anchor members. There was also another sale that RCL would include prepaid gratuity but only above certain categories were eligible.

She sent me the PDF file so I could see the sale prices would be, as well as whether it would make sense to book higher category to get the prepaid gratuity or book the lower category for a better cost ratio.

If I use the online booking, I would NOT know the upcoming sale and would have paid a few hundreds extra already. These are last minute bookings that dont offer price protection. We NEVER book something 10 - 12 months ago - those you do get price protection all the way till the final payment which normally is due between 30 to 75 days depends on the length of the cruise. The longer the lead time also longer - i.e. you would need to commit much earlier on a long cruise than your generic 7 days Caribbeans sojourn.

After some number crunching, we picked the 11 days Holy Lands. While we were studying these, she has already held a desirable cabin on the HAL Noordam for us pending our final decision.

On next Monday I was ready to book and pay (75% of the payment is due upon reservation as the sailings were just 6 weeks away on RCL's, and 8 weeks away on HAL's), she was too busy to handle our multiple cards so she got an extension from both lines to wait another day.

When we finally sat down to do the payment phone call, I used, or intended to use, 2 AMEX GCs, an AMEX DL and a Citi HHonor. The 1st AMEX GC did go thru without glitch but the 2nd one did not. I called AMEX GC thinking may be the registration at AMEX end was messed up. It turned out that in the fine print - AMEX GC cannot be used to pay cruise lines! (the other 2 places are obvious being Casino and ATM). Such condition is NOT online when you order the GC, but in the fine print on the paper that came with your GC. We had a conference call and eventually been told by AMEX GC rep that the reason of decline. The AMEX GC CSR even went further to say the 1st GC may get kicked back despite the authorization went thru. So I told her to just put the $500 to the Citi HHonor instead. Both she and I monitored the AMEX GC payment that got thru - it never got kicked back. The bill was posted in 2 days and HAL got its payment.

I dont see HOW I can do all the above with an online agency or with an agent that I only get to do business with thru some cruisecompete quote or thru a consolidator where it has just employees not a professional with industry credential. My cruise agent works as part of an AMEX Travel Services Consortium - google it you would understand what it means, and has full credentials. Her home office system directly links to cruise lines' booking system including the payment interface. She normally does not do agency checks but client's CC directly pay to cruise lines.

On every cruise we booked, we would get an invoice from her office with the breakdown of the commissionable portion, port charges and taxes. I also ask her to send me the Guest Copy of the Invoice which often shows a higher amount than we actually paid when it is HAL or Princess cruise which allow agent discount. The Guest Copy of Invoice also is good to have when you have Shareholder Credit / future cruise credit / agency credit - they show up on the Guest Copy of Invoice one way or the other. I always bring this with us just in case the shipboard account does not reflect that. So far we never have any issue.

As for the declined AMEX GC, the AMEX GC rep offered to refund the card value. I got a claim number on it. The process takes 20 business days but you can ask a supervisor to escalate it by sending an email request to the office in Utah, make it a 7 to 10 business days.

This is the first time the 2 ships go to Galveston I think. Both are much nicer than the Carnivals sailing out from Galveston.

In general YES. However this season RCL has 2 Voyager class ships as mentioned above, and Crown Princess will go to Galveston on Dec 22 as her final port of Transatlantic Westbound. It is because of that we decided to sail HAL's Noordam instead - because if we get off at Ft. Lauderdale, we lose 3 days on Crown's itinerary onto Galveston. If we stay on, flying home from IAH on Dec 22 would be either a very expensive pursuit with pay ticket, or a forced stay in Texas till Dec 24 or beyond. Either option is crappy so we decided not to sail Princess. We really should though because we are in need of 3 more Princess cruise to reach Elite so we get free laundry! But the way we keep deflect to HAL, we may end up being 3 star Mariner before we reach Princess Elite.

I priced out the UA bonus offers on our coming sailings - they are a few hundreds higher than what we paid, on 2 miles per $1. That is some expensive miles!