There are many cruises to choose from. "Cheap" or Budget" isn't always the best choice. Especially if it turns out not to be the experience you were hoping to have on a cruise. Find a local cruise certified travel agent and tell them the type of experience you are wanting on a cruise and the budget you have to spend. They can help match you to the right cruise.
There are some all inclusive lines that may sound more expensive up front, but in the long run are actually more cost effective. As Cruise Fanatic states, "Deals" are not always as they seem. I agree 100%, find a good cruise consultant/travel agent.