I purchased a used 2011 S1000RR that had a Brock's Performance Black 14 inch Alien Head exhaust on it. The bike was purchased by the original owner in April 2012. He used it about three weeks and then it sat until I bought it. It had 1300 miles on it when I pulled the exhaust off. The exhaust is in perfect shape no scrapes, dents etc. Some of the paint came off where the pipe joints fit together and where it is bolted to the bike and I seem to have misplaced two of the exhaust springs. They can be purchased from Brock's for $2.10 each. Asking $800 which includes shipping within Continental US. I am going to list on eBay as well, but will cancel eBay listing if someone here wants it.
Brock's Performance Black Alien Head 14" BMW S1000RR Full System Exhaust | eBay
link to ebay listing