Aksarben,
I think you might be mistaken here. From my understanding no priority points are needed to keep seats that you currently have. Priority points only help you to move up in line when it comes time to request new seats. Once you have seats, you only have to pay the ticket price plus the listed donation ($0, $50, $100, etc.) to keep those seats. If you've been told something different, that's not what I was told by people at the ticket office. My tickets are up in the 300 level and require no donation, so you certainly know more about the process than I do, but I did inquire about donations this year with the ticket office.