Ski all of Scotland on one season pass

It appears that there is an ‘all-in-one’ ski pass for all five Scottish ski areas (Cairngorms, Glencoe, Glenshee, Nevis Range and The Lech), and the cost is £389. There doesn’t appear to be any details on the site at http://www.snowsportscotland.org/, however, an email to lisa@snowsportscotland.org should get the necessary information. It should be noted that ticket numbers are limited (why?).