I've been checking Flippa from since it was still a part of SitePoint, and about 80% of their listings are those "turn key" sites. Of the remaining ones, there

I've been checking Flippa from since it was still a part of SitePoint, and about 80% of their listings are those "turn key" sites. Of the remaining ones, there is usually something fishy, like selling copyrighted content etc. Occasionally there do seem to be legit sites for sale as well, and having a separate category for "premium sites" has helped.