I never like relying on "can rent out the points." As the supply of
DVC points continues to grow, it can get harder to rent them out. But also, it's not easy to economically rent out each and every unused point. If you have 7 left-over points, you're never going to find a renter who wants exactly 7 points. There will almost always be points going to waste.
But for that reason... knowing it comes up fast where you might not go as often as religiously, it's why I prefer erring on the side of too few points as opposed to too many. You can always shorten a trip by a night, or try to book a cheaper resort or cheaper room category, you can always bank or borrow a few points, of even rent the additional points you do need. But getting stuck with unused points it just a waste.