You're not going to get a shit ton for $20. Best chance is Trout: http://www.troutartsupply.com/store.php?Ironlak-pg1-cid56.html
Or Oink.
The points are for Australia only. A link used to be posted in one of their images on the front page, but it's not there anymore. Basically you save them, and trade them in for merch.