I know this is a pretty old thread, but I just came across it on Google, so I figured I'd reply
It really depends on the condition of the sight, whether you still have the original box, paperwork etc. What do you WANT to get for it, if its stil available ? I may be interested in it, and I don't wanna throw a price out there, because that was the true meaning of your post - to find out a fair price - and I don't want it to seem like i'm giving you a price that is lower than the value because i'm interested in it.