Get an account signed up at all 3 websites if you haven't done so already - the FIRST RUN of every colordmd released so far has always sold out very quickly (and it is usually a 2-3 month gap before the next run)

My experience:

Colordmd has the most stock on hand but also the most traffic competing for one so can be hard to time it right to throw one in your cart with everyone else trying to add one to their cart at the same time.
BAA - has limited stock but better chances of securing one.
Planetary - even more limited in stock but it is the site that just about everyone overlooks/forgets about at the time so it is much easier to just log in, throw one into your cart and you are done. Hint Hint 

Also, the time zone factor - release times are US and they have always been late night early morning releases for Aus time (past midnight). So set your alarm clock!