New, unfired Remington and Winchester goes for just over 60 dents a case in .338 Win Mag, and if this is new and unfired, you might be able to get most of that out of it. If it was fired and you don't know how many times it has been reloaded, I know I wouldn't want it at all. If it has been once-fired, and that is certain, I would not personally be willing pay more than .20 a case for it because magnum brass is short lived to start with, and if it is sized down for firing in a different chamber, it may be still shorter? Others might feel differently, especially if they are desperate to find some?
If the brass is Lapua or Norma, I would pay twice as much for it.
