I am considering CBSubs for my sports club's site as a means of gathering online club subscriptions - i.e. payments for club, not site, membership. The difficulty I see is that club memberships involve potentially multiple people (couples, families) with different 'plans' (rates) based on their age or other user factors such as when they are allowed to play. I tried AEC but it didn't cope and I suspect CBSubs won't either as its aimed at a different purpose: paying for access to site functions.
Hence, I think I am going to have to build this myself.