Visit the Prince Resorts Hawaii website (see References). Click on Best Rates to see discount rates for the year. After reviewing these, click on Specials and Packages, then Special Offers. These offers often include a $50 resort credit, an additional night free or meals included with a room. Sign up for the special offer e-mail notifications if you're not traveling for awhile and don't see anything you currently like.
Research vacation websites that have agreements with the Prince Hotel, such as Let's Go Hawaii, which offers reasonable rates as well as plenty of tips on all there is to enjoy at Hapuna Beach. Blue Hawaii Vacations also includes discount offers when available. Occasionally, booking on travel websites such as Expedia can also yield a discount.
Book your activities first. If you will be kayaking, snorkeling, para-sailing or taking a tour while in Hawaii, book these first. You can sometimes find a package discount including a room at the Prince Hotel and various activities. By planning the majority of your trip ahead of time, you leave yourself plenty of time to find accommodations and may find an unexpected deal.
If you go to Hawaii often, or would like to make it a regular vacation spot, consider joining the Prince Preferred program. Through the hotel itself, you can accrue points every time you stay at the hotel. You will also receive special discounts and airline miles. You can also personalize your stay and earn free nights at any of Prince's Hawaii hotels. Membership is free, and can come in handy for future discounts.