I don't know about the price issue, but I know you'll thank yourself for having Katamari in your collection. It's the kind of game you can just pop in at any time and have fun with. Looking at your collection, it seems like you have almost nothing except story-based games. So having a simple game like Katamari on you might do you good for when you've exhausted all your other games. Of course, if Chojin's right about the price, you should probably wait until you find it cheaper.
Or you could just play solitaire. Whatever.
Threaded Mode