It is not always true that you get better value renting your points and then paying cash for the cruise. It all depends on how far in advance you can plan, which season, and what the going rate is.
We decided to cruise on the upcoming 12/17 Magic pretty late in the game (for planners, anyway). We decided on the trip this summer and booked the last group cabin available via a well known
DCL TA in August. The group rate negotiated way back about 1 1/2 years in advance when rates were first released by DCL, and as of the time we booked the cabin the then "current" retail rates (even through discounted TAs) were roughly $1500 more for our cabin.
Shortly thereafter I tried to search for another cabin for my mom. I searched for about a month, well into early October, and with no group rates left with any TA (because DCL makes TAs give up group space booking a certain amount of time in advance), we were priced out of any of the inside cabins for one person. I looked into
DVC and discovered we could get the inside cabin, cat. 11, for one (paying a single supplement) with points that come to roughly
$1000 less than the price for paying cash. (I currently value my points at roughly $6.25 a point, taking into account the purchase price, number of use years remaining, and our annual maintenance fees. Obviously, those who bought into DVC much earlier than we did would have a lower cost per point.) Indeed if we had rented all the points necessary to book that cabin using DVC points, even at $10 a point, the cash proceeds BEFORE taxes on the rental gain would still be
a few hundred dollars short of the best current cash rate we could get for that cabin.
The lesson is always comparison shop. I know the rule of thumb on this board is "don't use your points for cruises" or "always rent your points and then pay cash", but that is not always the best course and in fact could end up causing someone to pay significantly more for the cruise.