I use a TA but only after I have looked at several websites and this gives me a double check that my TA is current(I have no connection with the cruise industry and my purpose here is to help as much as I can). However, please note that the cruise lines control the pricing, that is, they tell the travel agents, consolidators, and others what the price of each cruise/cabin will be. Having said that, your task is to seek out the good deals that each cruise line offers from time to time. The websites are Vacations to Go, Icruise, Expedia, Orbitz, Ovestock.com, and Affordable Cruises. Also, check with each cruise line directly.
Hope this helps.