Typically cruise rates are cheaper when school for kids in session. People who wish not to have very many children onboard may want to consider cruising during this off-season time. Keep in mind that very few cruises are 100% kid-free because of homeschool and parents pulling their children out of school.
The type of stateroom that you choose will have an impact on the price you pay for your cruise. If you get an interior stateroom with no view you will most likely have a cheaper rate than a person who books a suite with a balcony. Research stateroom categories and their prices and then compare the price & value before making a decision on the type of stateroom that you will stay in. Often interior staterooms are a great way to try cruising at a lower price, but getting a room with a view will allow you to get a chance to see outside.
Finally, before you book your cruise make sure you know what is included with your stateroom category and the price of your cruise vacation. You can often find what amenities are included on your cruise line's website. It is your responsibility to find out what you get for what you pay for. Make sure you know this information before getting onboard the cruise ship because expecting more than you actually get could lead to disappointment.