The way I see it, selling a website raises many questions. I am looking at this from the potential buyer's viewpoint.
First, why does the owner want to sell the website?
If the website is functioning and making money, it does seem strange that the owner would want to part with it. Alright, maybe the owner is getting bored and wants to do something different. Or, the owner is getting old and wants to retire with a lump sum of cash. I don't really know. Can you imagine that, say, Mark, when he gets old and tired of running a business, would sell Facebook?
Two, if the website is not functioning and not making money, why buy it? For the domain name? Well, from what I can remember, at one time, the record price for a domain name was the amount paid for sex dot com. Now, does anyone know what happened to that domain name or any website with that domain name? I have seen some forums being bought and merged. So far, I have not heard of any good news about such activities yet.
Now, don't let me discourage you from selling your website, or buying one. Just be careful. Cyberspace is full of black holes, waiting for the unwary.