The only way I'd like this "Hidden Litter Planter Box" more is if it could somehow compost the cat leavings into something nutritious for plants. Considering that feline droppings and urine are about the most toxic substance emitted by mammals, I'd say that's unlikely.
Until that sweet day when ammonia won't kill a fern, this planter will have to do. Sure, it's tacky, but not any more than any other exposed cat box, a problem that many of you with big houses in the 'burbs may not understand, but apartment dwellers know all too well. (Other designs are available but they're all about as goofy looking.)
Prices vary based on materials, but they're all in the $80 to $180 range.