I'll shortly be getting rid of a Burris Black Diamond 6-24x50 SF with the ballistic mil-dot reticule. Anyone hazard a guess what it would be worth, in mint condition? They're so rare here, you never see them secondhand, so knowing what to ask is going to be an issue. I might even put it on here simply because they're better known in the UK.
http://theopticzone.com/detail.aspx?ID=2015