You can argue that the difference isn't worth the effort of renting, but it is
never more cost effective to to exchange into the Disney Concierge Collection.
Even if we cherry-pick the 19pt/night at Caribbean Beach (the only resort with a 19pt/night room), and say we stay Sun-Thurs, specifically during the period that is covered, Jan 2-3, Jan 7-11, Jan 15-Feb 14 (Adventure Season), each of those 19pt nights would cost $203.06/night (incl. tax). 19 points renting at $13/night will yield $247.00.
Assuming you stay for 5 nights maximizing the 19pt/night rate, that would cost you as follows:
CASH
$1,015.30
POINTS
95
If you were to rent those 95 points at $13/point, that would be $1,235.00. A $219.70 difference, or 18% difference.
The equivalent is renting out 78 points. A savings of 17 points.
All that is not to say one should rent out their points to stay elsewhere, it's more to underscore why it is repeated on these boards over and over again: don't buy into
DVC unless you plan to use your points at a DVC resort. Using those direct point "benefits" only benefits Disney.