Not completely sight unseen on the buy of my 11S in '08. Tons of pictures, and a few phone discussions convinced me to pony up with the bucks...in person. The risk involved was purchase of a cheap one way flight to Louisville, KY assuming the bike was as advertised on CL. It was, and completely satisfied with the purchase. Of course, my spouse thought I was crazy...but what else is new!
That being said, I'd be pretty cautious with eBay, and I trust PayPal about as far as I could toss a Greyhound bus.
BTW, took me six months of due diligence searching the country for the "right" deal for a gray/mandarin '04 11S...the patience was rewarding.
Best of luck!
Bill J