Its all down to supply and demand.
The DREAM can accomodate 1.5 times the people of the Magic and Wonder, so from 2011, there is accommodation increase of 175%.
The DREAM being larger has economies of scale, so covers its fixed costs quicker.
Now then there is increased competition other cruise lines are increasing their capacity, newer ships more facilities, so
DCL has to compete in an aggressive market.
I always thought its best to release cruises at a reasonable price, rather than a high price, and then discount when they do not sell. As the current practice of DCL, favours late bookers, and people book later for a deal or in hope of an upgrade in port.
Unrealistic Suite prices, and now leaving these 'unbooked' and forcing a fire-sale in port on embarkation.