There are two different factors involved: (a) how many points are required for the reservation, based on the
point chart for that particular resort and those particular dates, and (b) how much you have to pay per point.
So first you have to know how many points are needed.
Then you need to know how much you would pay per point.
If you are renting from an agency, their website might show that they charge more for reservations which are between 7 months and 11 months out. For example, it might be $20 per point if the reservation is between 7 months and 11 months out, and $19 per point if the reservation is less than 7 months out.
If you are renting from an owner, they decide how much to charge per point.
Sometimes someone already made a reservation which they can't use and they want to rent out that reservation rather than cancel it to get their points back. The closer it is to check-in date, the more the price might drop.