The subscription option is now removed from the JAMM page. With three issues left, it didn't make much sense to keep it there. You can now either buy the entire first volume (and receive the JAMM deck when it's available) or purchase individual issues.
The final three issues of the JAMM will be
November: The Thanksgiving Issue - I will be giving thanks to some people whose ideas have influenced me and offering some ideas inspired by their work.
December: The Holiday Issue - This issue will have a few effects that use magic in the context of gift giving.
January: The New Years Issue - The New Year is a time for change and reinvention. This issue will feature a couple of effects that may inspire or motivate your spectator along their path in that regard.