Amazon is selling select Pixel Pals for $9.99, matching Gamestop's $9.99 Black Friday deal on Pixel Pals.
At the time of this posting, this is a better choice over Gamestop as Amazon has more of these in stock and has free shipping for Prime members as an add on item. If you're buying something from Amazon anyway and have your eye on Pixel Pals, add one for $10 each.
Super Mario World (which is only preorder on Gamestop) is in stock on Amazon, Super Mario Bros 3 Luigi (sold out online on Gamestop) is also in stock.
I'm assuming the Pixel Pals that are $14.99 are due to being sold out or on pre-order on Gamestop.
Edit: These are no longer an add-on only item!