Download the designs from the Cubeecraft website and build these paper psychos yourself- you only need a printer and some scissors. Oh, and patience. And love...let's not forget the love.
There are about a zillion designs to choose from, from comic book icons such as Batman and Hellboy to such random characters as the "Duck Hunt" dog. I started out slow and simple and made myself a sweet-n-nerdy little Weighted Companion Cube* from Portal**.
Someday I hope to advance my folding skills and paper fu enough to tackle Chairy!
* that link plays "Still Alive", which WILL get stuck in your head
** i heart Portal