unfortunatly in this day and age, I'd treat selling to the public as though they will tried and steal it off you.
there's plenty of intellegent gangs out there who can persuade you to part with your bike.
Likewise there will be peeps who will be just as paranoid buying bikes from peeps they do not know.
If you are buying your bike from a dealer, why not see if a part ex deal might be better?
ebay is also a good place to sell on, but again whatch for unsolicited emails etc.