Be aware of renting cards on the season's lats hours. Some of your rented cards may be cancelled and you will need to rent new ones. I've already lost 3 or 4 cards in couple hours. Trying to rent gold cards at the end may not be that easy. Good Luck for all!
As long as you rent them within 24 hours of season end they can't be cancelled. Of course prices also spike at that time.