We sometimes book our own trips, sometimes use an online agent. For a transAtlantic cruise in Sept. we're using an agent. He tells me he may be able to get better, cheaper flights for our cruise because he is a consolidator, or has a consolidator, or something like that. Just curious about a flight consolidator, and how they can benefit us.

Sort of like a broker. They buy tickets in masse or bulk from the airlines then resell them to TA's who sell them to you. Not sure how this saves you as the ticket has been stepped on twice B4 you pay so there are two profits first.
Then there is the matter of what kind of ticket you get. Just be sure it's legit. I 've heard of people ending up with standby tickets only they did not know that at the time of purchase.

Over the years I've used consolidators several times. Never ever has standby been involved.

Cheapoair, cheaptickets etc. Totally legit.

But w/ all the reduced capacity, I don't think consolidators are as easy/cheap as they used to be.

A consolidator is a ticket broker. Many sell directly to the public, and some (Centrav, for example) sell only to travel agents.

Some of the consolidators have access to cruise-only air fares. Cruise-only fares are sometimes several hundred dollars less than the least expensive fares otherwise available. To be eligible for these fares, the client must be going to/from a cruise, and the client may be required to show the cruise documents when checking in for the flights.

A Flight Consolidators are brokers who purchase Flight Tickets in bulk and then resell, either to travel agents or directly to consumers for attractive discounts.

It turns out that our TA wasn't able to get our tickets at a good price, even with the consolidator. I went directly through Princess Cruises and got what I feel is a pretty good price. I would like to hear your opinions about our flight costs. I'm still learning. We're cruising from Copenhagen. Our flights from Dallas,layover in Amsterdam, then to Copenhagen, then at trip's end,from LaGuardia,layover in Cincinnati,then to Dallas, were $836 pp, including taxes, etc.

That price is ok, but you probably could have done slightly better. I also would have tried to avoid the unneccessary connection (in CVG) on the way home.

I don't know which specific dates you're traveling. But for next September, I could see availability on consolidator fares from Dallas to Copenhagen for $586, and then a published fare (that is, a fare that customers can get directly from the airline) for about $70 for LaGuardia to Dallas. Importantly, the LGA-DFW flight is non-stop, not changing in Cincinnati. Any travel agent would also add a service fee to those fares, as neither pays a commission.