All responses from Cruise Compete come from licensed sellers of travel. Almost all people have had good luck with Cruise Compete.
With all agents make sure that you pay with a credit card and that the charges are made to the cruise line and not to the agency. Also make sure you receive your cruise line booking number after making your initial payment.
You should also make sure that the price quoted includes ALL costs including all taxes and port charges for the category cabin you requested.
It is also a good idea to get the name and contact information on who to contact in the event your agent is unavailable if and when you need them.