This sounds like a flippant reply, but it really isn't...
You could A) Pull a number out your arse and then spend a few days arguing on GFY with people who tell you you are unrealistic, or B) Decide what you want for it and get people to make 'Best Offers' to you via PM. Then, if any are near ballpark, talk further.
Its only ever going to be worth what someone is willing to pay for it, so pointless to waste time arguing
Just my
