For the chowhound looking for the larger-sized couscous..... Whole Foods (at the Kahala Mall) is the answer to your question! It's in the pasta/grain aisle, right next to the Middle East brand boxes of grains. I think it was about $4 for the box.
I'm going to warn you, though..... you're probably going to walk away from Whole Foods with a whole lot more than just that box of couscous.