I've never been on an E&E or SERE course, but I'm guessing there must be similarities if the aim of those is avoiding detection using limited kit, speed, stealth and endurance to get you through. There is an offer of these guys running a course in the near future on how to play, and teaching basic skills in order to be able to start some kind of league, but finding like-minded individuals is proving a bit difficult. Part of the problem is, as you've probably guessed, it's not cheap to run. The main problem with keeping costs down is the insurance that's required given that it's low numbers