I just saw your question as I was looking for something else. If you still need an answer to that question, AARP sells Princess (as well as other cruises') gift cards for 10% off. There is currently a limit of 5 per month with options of $500 gift card for $450 and $100 for $90. It's not that easy to find, but under the REWARDS section. Even if you use a TA, you can still use them to pay off a cruise.