The points vary wildly depending on duration of the cruise, itinerary, room category, number and age of those in your party. Unless someone else knows of an on-line resource for the current chart, I'd suggest contacting
DVC and have them send you a copy.
Also note that the point costs for cruises do increase annually, unlike the costs for using points at DVC resorts which remain fixed. Using points for cruises is a nice option to have available, but most people here will agree that the points charged by DVC are abnormally high compared to other uses of points.