Best Buy has the 13-month cards on sale for $30 this week. I'll be picking up a couple.
http://www.bestbuy.com/site/olspage.jsp?skuId=7530246&st=xbox+live&type=product&id=1127507946517
http://www.bestbuy.com/site/olspage.jsp?skuId=7530246&st=xbox+live&type=product&id=1127507946517