I agree that it is definitely worth it. Travel Agents typically get 15-16% in commission. I have received as much as 13% in cash back, fare discounts and/or cabin credits. (That was when cruising had just re-started after COVID and agents were hungry.) On another cruise I got 10% back. I recently booked a 2 week cruise for my son and DIL and got them an additional $400. off the fare and $600. in cabin credits. Here is my process:
First, I comb this forum (which I greatly appreciate) for any discount codes, then I book the cruise myself. Once I have my confirmation of the booking I go to a site that will allow travel agents to bid for my business. I don't know if I am allowed to post that link, but if you put "New tool lets cruise agents bid for your business," it will take you to an article with the link to that site. You have to register for a free account. Then I post on that site that I have already booked the cruise, give the date and ship and cabin number. In the notes section, I ask that the bids include any discounts or cabin credits. Within 1-3 days, I will get 5-6 bids and I just pick the best offer. I give them a call and give them my booking number and they call Viking and have the booking transferred to their agency. I really don't expect any other service from a travel agent--I prefer to do all my own research, choose my own flights etc. So its a win-win for both of us. Within 14 days of booking, I will purchase travel insurance checking both Squaremouth and InsuremyTrip to compare policies/rates (doing it within 14 days gets coverage for any-pre-existing conditions). Then I call Viking and ask them to be sure to send my documents/luggage tags to my home address, otherwise they will send it to the agent. Last I make sure when I receive the new booking confirmation from the agent, that my discounts and cabin credits are shown. Keep in mind, that you have a limited length of time to transfer a booking to an agent. I think with Viking it is 60 days, but I do it as soon as possible. Then, 10 months before the date of debarkation, I go online and choose flights, call Viking Air Plus and ask them to book. With Air Plus, I don't have to go through the agent. So that is my process, gleaned from many years of booking cruises. There is only one way that I know of to get a better price... and that is to become a travel agent yourself. Hope this helps and safe travels friends.