This will be gone soon. Amazon is stacking the lightning deal price of 3 3DS games with a promotion that is meant to buy 3 for $25.
Go to lightning deals and add these 3 games to your cart (about 55% claimed at the time of posting). You must add all 3 to get the deal.
Nintendogs + Cats: French Bulldog and New Friends
Nintendogs + Cats: Toy Poodle and New Friends
When you go to check out, the total at first will be about $25 (I don't remember exactly). But when you go to actually pay a $17.92 promotion will be applied bringing the total to $8.87.