How badly is it scratched? Mine had light scratches on it and I used Plast-X to polish it up. It looks much better now. You won't get deep scratches out, but it will remove or improve lighter scratches and get rid of haze. There are other plastic polishes out there, I've only used the plast-x so I can't speak for the others.
Here it is for half that price. http://www.factorychryslerparts.com/.../04874345.html
Interestingly enough, it looks like that same part number fits grand cherokees as well. You may be able to find one at the salvage yard. Wranglers are hard to come by at salvages, but cherokees are more plentiful.