I'm new, but I think this is how it works:
If you want a 405,000 point reservation, and it is within 90days, you can borrow points that you need over and above your 300K to make the reservation.
But, if you are making it in the Standard Reservation window (10 months out), you cannot borrow points.
I just went through this scenario and worked around it this way:
I wanted a reservation in June 2015 that was 26K points more than I had available for next year. I made a reservation for January 2015 (within the 90 day window) for the total I needed and that allowed me to borrow those 2016 points. Then I cancelled the reservation. By doing that, those points become "cancelled points" that must be used in the year the reservation was cancelled in....so, I was able to borrow points that way to use in 2015 from 2016.
Also, be aware that the resale can take A LONG TIME to register with Wyndham. I purchased 2 contracts. One in June, the other in July. The June purchase just got registered with Wyndham last week. Start to finish, it was a 4 month process. I am still waiting on the July contract to be recorded with Wyndham.
We used Timeshare Transfers. They were great and moved fast. The slow part is Wyndham. When I called they said it is a 7 week wait once they receive all the paperwork.
Hope that helps.