like pilot said
EBAY all the way.
the only thing is that it may not be available right away. if you plan ahead of time, you may be able to watch ebay until the right one comes up. you can set it up so that ebay will let you know what items are new each day. good luck.
ps. i bought my backrest, rack, and mounts off ebay cheaper than the backrest itself would have been through kawi, and the thing is as good as new.