Why did you buy in the first place when you "could rent at $10 a point" and never have any annual dues?
Will you
always be able to rent at $10 per point? The rental rates are definitely higher now than they were a couple of years ago. I'd always prefer the peace of mind when making my own reservations and that, by itself, would cause me to want to add-on if I knew I needed more points each year.
Good luck with your decision.