Of all the play sets, it's these Jenga ones that are the best value I reckon, unless you really need more Karts in your game.
Not only do you get a nifty little Jenga spin-off, such as this one in which you fire Karts at a pirate ship until it tumbles, you also get a code to unlock the Jenga minigame in the app itself.
It's not possible to teleport the Karts into Angry Birds Go! though, as far as I can tell at least.
If you want one of these, you can grab one on Amazon.
For a full list of the Angry Birds Go! toys and sets, click here.