Quintuple Points Card
The Quintuple Points Card is a reward card from Spirit Tracks. This card works like a coupon, and can be used to purchase a single item from Beedle's Air Shop in which Link will then earn five times the amount of points.
Link acquires the Quintuple Points Card alongside the Platinum Card when Link has earned 1,000 points from the shop. Link earns 1 point for every 10 Rupees he spends, so he will need to spend 10,000 Rupees to acquire the Quintuple Points Card. The only card beyond the Platinum Card that Link can acquire is the Diamond Card. Thus, the only purpose for the Quintuple Points Card is to making it easier to acquire the Diamond Card and to 100% complete the game.