My TA gives "rewards" on every cruise varying from 5% to 7.5%. The rewards come in a check about same time I receive docs. At first I thought it was kind of silly for cruiseline to enforce a fixed price but then letting my TA give rewards but I quickly realized I am earning miles on the whole amount including the 7.5% I get back.
Also, as Kuki mentioned, she is allowed to sell "group space" at lower rate on a certain number of sailings per year so her prices will be cheaper on those cruises as the cruise line raises prices.
"The test of a first rate intelligence is the ability to hold two opposed ideas in the mind at the same time and still retain the ability to function."
F Scott Fitzgerald
Silversea Silver Explorer (23nts) - Kangerlussuaq, Greenland - Nome, Alaska - Aug 14
Seven Seas Voyager (30nts) - Dubai - Cape Town - Nov 14