You'll probably never find that
renting points for a non-
DVC resort would ever save money, and most likely would probably cost more than reserving the hotel room through CRO.
Suppose you can get points for $10 each and you want to stay at the Poly later this month, Sunday through Thursday night (5-nights). That's 49 points per night for a Garden view, or 64 points for a Lagoon View.
5-nights garden view would be 245 points. Or $2,450 at $10/point. Plus $95 booking fee, so a total of $2,545. That's an average of $509/night.
Want to stay 7-nights, and have a Lagoon View, it would be 550 points. So at $10/pt plus the $95 it would total $5,595. Or an average of $799.28/night.
Want to go as cheap as possible, then it's Carribean Beach, Port Orleans, or Coronado, in January, Aug, Sep, Nov, early Dec. 16 points/night weekdays, 29 points/night weekend. go for 7-nights and it's 138 points. So you'd be looking at about $1,475 or an average of $210/night. Now I don't know offhand the rack rate for these resorts, but I'll bet anything that in January they're less than $210/night.