When I'm not in a regular game, I tend to compensate by buying new/more games/game books
I tend to buy more when I'm in an active group - ie, gaming increases my desire to have more game stuff.
I buy a lot of games/game books period. I'm a junkie. I need to join GBBA.
I only buy stuff that I REALLY want, regardless if I'm in a group or not or active or not.
Other (explain in a comment)