Depends on how your able to set up the files aswell as the dedi. You could have the best dedi in the world but if you can't set up the files that well your server will suffer from constant crashes and people gett d/c,
But anyway i would say 2000 - 2500 players seems to be somewhere realistic even though it's highly improbable you'll even get that many players due to the competition.
Your better off starting small then expanding if your sucessfull, e.g upgrading.